Articles de revues : « Stokes (Computer program) »

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Cao, Wei, Chuan Fu Xu et Zheng Hua Wang. « Heterogeneous Computing for a CFD Solver on GPU/CPU Computer ». Advanced Materials Research 791-793 (septembre 2013) : 1252–55. http://dx.doi.org/10.4028/www.scientific.net/amr.791-793.1252.

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The high-order schemes have attracted more and more attention in computational fluid dynamics (CFD) simulations. As a kind of high-order schemes, weighted compact nonlinear schemes (WCNSs) have been widely applied. In recent years, the highly parallel graphics processing unit (GPU) is rapidly gaining maturity as a powerful engine for high performance computer. This paper studies the heterogeneous parallel computation and implementation of a high-order CFD program on Tianhe-1A supercomputer system. The CFD program is intended for the solution of the Navier-Stokes equations on multi-block Cartesian meshes for aerodynamics research. The solver utilizes the high-order WCNS scheme for space discretization and Jacobi iteration method for time discretization. The performance analyses show that the single-GPU solver achieves about 8× speed-ups relative to a serial computation on a CPU core.

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Akgun, B. Tevfik. « The Digital Art of Marbled Paper ». Leonardo 37, n^o 1 (février 2004) : 49–52. http://dx.doi.org/10.1162/002409404772828120.

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The author describes his development of a computer-based paper-marbling tool, based on a traditional Turkish art form in which marbled-paper figures and patterns are created on the surface of a liquid bath. Similar works can be obtained by simulating fluid flows on a computer, using the Navier-Stokes equations as the physical model of the fluid flows. The author has created an application program that includes marbling tools. Such a program must run in real time, so that hand-eye coordination is required of the user. Real-time simulation of fluid flows requires much processor power. The author has attempted to adapt this technique for use with a personal computer. To decrease the processing power required, the image size may be decreased, but the results may not be as satisfactory

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Aktaev, Nurken E., et Tatiana A. Penkina. « Applicability of the approximation of Stokes for calculating the velocity of a steam-air jet over a locally heated water surface ». Tyumen State University Herald. Physical and Mathematical Modeling. Oil, Gas, Energy 6, n^o 1 (2020) : 166–75. http://dx.doi.org/10.21684/2411-7978-2020-6-1-166-175.

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This paper presents a mathematical model of an air steam flow arising above a locally heated water surface. The model is based on the system of equations of free convection in the Boussinesq approximation and is implemented as a computer program in C language. Numerical simulation aided in obtaining the velocity fields of the jet are obtained at various values of the water surface temperature. The values of the flow velocities obtained in the framework of the Stokes approximation are compared with the calculated values based on the results of experiments on the levitation of water droplets. As a result of the comparison, the condition of the applicability of the approximation of Stokes to estimate the velocity of an air steam flow is formulated.

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Uzoma, Mathew Shadrack. « APPLICATION OF THE DEDUCTIONS FROM NAVIER STOKES EQUATIONS FOR THE DETERMINATION OF FLOW VELOCITY AND THROUGHPUT IN A GAS PIPELINE BY COMPUTATIONAL APPROACH ». European Journal of Physical Sciences 1, n^o 1 (17 septembre 2019) : 1–9. http://dx.doi.org/10.47672/ejps.400.

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Theoretical treatment of gas pipeline pressure-flow problem had been presented applying Navier Stokes equation reduced to their appropriate forms by applicable practical conditions. The results obtained from the theoretical analysis tally with the operating conditions of the case study pipelines. The pipelines being Shell Petroleum Development Company (SPDC) and ElfTotal Nigeria Limited. The results obtained by numerical discretization suggested that these pipelines are not optimally operated. Hence, the need to adjust the flow situation to bring pressure and flow throughput to optimal level of performance. Throughput in excess of the operating conditions could be accommodated by these operating pipelines. It is imperative that this could prevent the spread of these vital capital intensive assets. The funds so conserved could be diverted to sourcing for new gas fields to increase the nation’s strategic reserves.Purpose: The purpose of this work is to enable comparative analysis of the results of the deductions from Nervier Stokes equations with that generated by computer simulation of the discrete formulation.Methodology: Outlining the deductions and developing the discrete formulation. Computer program was developed for the discrete formulation and operational data from operating gas pipelines injected both for the deductions and computational algorithmic coding and the deduced expressions from the Nervier Stokes equations. Results obtained were compared in a bid to address line throughput subject to the operational conditions of the specified gas pipelines in this study.Findings: The output results of the Nervier Stokes deductions matched closed with operational throughput of the two gas pipelines. The numerical discretization simulation results confirmed that additional throughput far and above 1.8m3/s could still be accommodated by these gas pipelines.Unique contribution to theory, practice and policy: As earlier predicted, our existing gas pipelines are grossly under-operated. Additional capacity much more than the operational capacity could still be accommodated by these gas pipelines.

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Kalis, Harijs, et Ilmārs Kangro. « VORTICAL FLOW OF INCOMPRESSIBLE VISCOUS FLUID IN FINITE CYLINDER ». Mathematical Modelling and Analysis 13, n^o 3 (30 septembre 2008) : 371–81. http://dx.doi.org/10.3846/1392-6292.2008.13.371-381.

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The effective use of vortex energy in production of strong velocity fields by different devices is one of the modern areas of applications, developed during the last decade. In this paper the distribution of velocity field for viscous incompressible fluid in a pipe with a system of finite number of circular vortex lines, positioned on the inner surface of the finite cylinder is calculated. The approximation of the corresponding boundary value problem for the Navier‐Stokes equations is based on the finite difference method. This procedure allows us to reduce the 2D problem decribed by the system of Navier‐ Stokes PDEs to the monotonous difference equations. Calculations are done using the computer program Matlab and the following regimes are calculated: a) the flow in a smooth pipe; b) the flow, poured inside a pipe through the circle; c) the flow, poured inside a pipe through the ring. The model is investigated for different values of parameters Re (Reynolds number), G(swirl number) and A (vortex intensity).

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Dawes, W. N. « A Numerical Analysis of the Three-Dimensional Viscous Flow in a Transonic Compressor Rotor and Comparison With Experiment ». Journal of Turbomachinery 109, n^o 1 (1 janvier 1987) : 83–90. http://dx.doi.org/10.1115/1.3262074.

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The numerical analysis of highly loaded transonic compressors continues to be of considerable interest. Although much progress has been made with inviscid analyses, viscous effects can be very significant, especially those associated with shock–boundary layer interactions. While inviscid analyses have been enhanced by the interactive inclusion of blade surf ace boundary layer calculations, it may be better in the long term to develop efficient algorithms to solve the full three-dimensional Navier–Stokes equations. Indeed, it seems that many phenomena of key interest, like tip clearance flows, may only be accessible to a Navier–Stokes solver. The present paper describes a computer program developed for solving the three-dimensional viscous compressible flow equations in turbomachine geometries. The code is applied to the study of the flowfield in an axial-flow transonic compressor rotor with an attempt to resolve the tip clearance flow. The predicted flow is compared with laser anemometry measurements and good agreement is found.

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Leoveanu, Ioan Sorin, Kamila Kotrasova et Eva Kormaníková. « Using of Computer Fluid Dynamics in Simulation of the Waste Reserviors Processes ». Advanced Materials Research 969 (juin 2014) : 351–54. http://dx.doi.org/10.4028/www.scientific.net/amr.969.351.

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The paper scope consists in using the computational fluid dynamics for the simulation of waste reservoirs processes like the flood filling regime, flow over the dam in flood filling, and earthquake disaster. The flood regime may induce a particularly dynamics pressure on the dam walls and a particularly distribution of fluid flow inside liquid. On the other hand, when the disaster like earthquake occurs, the fluid dynamics and the induced pressures on the dam walls become extremely important for safety estimation of critical components. The dam break case is extremely important in management of safety buildings in the neighboring area of the reservoirs too. Solutions of these important civil engineering problems were obtained using the classical Navier-Stokes fluid flow equations. In the analyzed cases, the simulations were based for solving the problem of fluid with the free surface flow and complex boundary configurations by using an original program developed with MAC method.

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Giles, M., et R. Haimes. « Validation of a Numerical Method for Unsteady Flow Calculations ». Journal of Turbomachinery 115, n^o 1 (1 janvier 1993) : 110–17. http://dx.doi.org/10.1115/1.2929195.

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This paper describes and validates a numerical method for the calculation of unsteady inviscid and viscous flows. A companion paper compares experimental measurements of unsteady heat transfer on a transonic rotor with the corresponding computational results. The mathematical model is the Reynolds-averaged unsteady Navier–Stokes equations for a compressible ideal gas. Quasi-three-dimensionality is included through the use of a variable streamtube thickness. The numerical algorithm is unusual in two respects: (a) For reasons of efficiency and flexibility, it uses a hybrid Navier–Stokes/Euler method, and (b) to allow for the computation of stator/rotor combinations with arbitrary pitch ratio, a novel space–time coordinate transformation is used. Several test cases are presented to validate the performance of the computer program, UNSFLO. These include: (a) unsteady, inviscid flat plate cascade flows (b) steady and unsteady, viscous flat plate cascade flows, (c) steady turbine heat transfer and loss prediction. In the first two sets of cases comparisons are made with theory, and in the third the comparison is with experimental data.

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Wang, Gang. « Finite Element Simulations of Free Surface Flows With Surface Tension in Complex Geometries ». Journal of Fluids Engineering 124, n^o 3 (19 août 2002) : 584–94. http://dx.doi.org/10.1115/1.1466458.

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The finite-element program, ANSYS/FLOTRAN, has been enhanced at Release 5.7 to predict free surface flows with surface tension in complex geometries. The two-dimensional incompressible Navier-Stokes and energy equations are solved in both Cartesian and axisymmetric coordinate systems. At Release 5.6, the free surface capabilities have been incorporated into ANSYS/FLOTRAN using the CLEAR-VOF algorithm. The main contribution of this work is to implement a surface tension model into ANSYS/FLOTRAN to study free surface flows with surface tension in complex geometries. Both normal and tangential components of surface tension forces are modeled at the interface through a continuum surface force (CSF) model. This new algorithm is first validated with two model problems: a droplet in equilibrium and an oscillating droplet. For the first problem, the computed pressure value is compared with the theoretical value, whereas for the second problem, the oscillation frequency is compared with both the analytical solution and experimental data. The computer program is then applied to thermocapillary flows in two types of trapezoidal cavities to investigate the interesting flow and heat transfer characteristics. Systematic calculations are performed to study the influence of Marangoni number, capillary number and static contact angle on Marangoni convection.

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Singh, Bijendra. « Simultaneous computation of gravity and magnetic anomalies resulting from a 2‐D object ». GEOPHYSICS 67, n^o 3 (mai 2002) : 801–6. http://dx.doi.org/10.1190/1.1484524.

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This paper presents a new algorithm for the simultaneous computation of gravity and magnetic anomalies resulting from an infinitely long (2‐D) body with an arbitrary polygonal cross‐section. With the assumption of uniform volume density and magnetization, the gravity or magnetic field may be expressed as the field resulting from an equivalent distribution of surface mass density or surface pole density, respectively, over the surface of the source body. The resulting surface integrals are reduced to new line integrals using Stokes' theorem. The components of the fields for each bounding surface are expressed in terms of a new line integral and the solid angle subtended by the surface at the point of observation. Since these analytical solutions are similar in form, a direct relation is derived between gravity and magnetic fields, which allows their simultaneous computation. Hence, the same computer program can be used to compute the gravity field, the magnetic field, or both fields simultaneously. This new approach will find wide applications in the joint inversion of potential field data, as it will make the numerical computations much faster.

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Gaitonde, A. L., D. P. Jones et S. P. Fiddes. « A 2D Navier-Stokes method for unsteady compressible flow calculations on moving meshes ». Aeronautical Journal 102, n^o 1012 (février 1998) : 89–97. http://dx.doi.org/10.1017/s000192400006557x.

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AbstractA moving mesh method for the computation of compressible viscous flow past deforming and moving aerofoils is described. It is based on a well established time-marching finite-volume scheme, which has been widely used for steady compressible flows. An implicit real-time discretisation is used and the equations are integrated via a dual-time scheme. This involves the introduction of derivatives of a fictitious pseudo time. The solution at each real-time step involves seeking solutions which are steady-state solutions in pseudo time. This approach decouples the stability and accuracy limitations of the scheme and permits large real-time steps to be chosen. Also well-proven convergence acceleration techniques developed for steady flows such as local-time stepping, residual averaging and multigrid may be used in the pseudo-time stepping scheme without compromising real-time accuracy. A sequence of body-conforming grids and corresponding grid speeds is required, where the inner and outer boundaries of the grid move independently. The required grids and speeds are found using a transfinite interpolation technique. Applications of the method to external compressible flows are shown, including results from a parallel version of the computer program.

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Hassan, Ayad K. « PREDICTION OF THREE DIMENSIONAL NATURAL CONVECTION FROM A HORIZONTAL ISOTHERMAL SQUARE PLATE ». Journal of Engineering 12, n^o 03 (1 septembre 2006) : 742–55. http://dx.doi.org/10.31026/j.eng.2006.03.23.

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A theoretical study of a three-dimensional natural convection heat transfer from an isothermal horizontal square plate, with upper and lower heated surfaces is present. The transient Navier–Stokes and energy equations were solved by using finite deference method (F.D.M). The complete Navier–Stokes equations are transformed and expressed in terms of vorticity–vector potential and solved using an Alternating Direction Implicit (ADI) method for the parabolic portion of the problem, and Successive Over–Relaxation (SOR) method for the elliptic portion .A computer program in (FORTRAN 77) was built to carry out the solution. The numerical results were obtained for laminar flow range of Grashof number up to (105) in up ward–facing and downward–facing with Prandtl number of (0.72). The results of local Nusselt number have maximum values at the outer edge of plate for two cases upward and downward facing heating.The comparison of the results of average Nusselt number with numerical data for downward facing and experimental data for upward facing shows acceptable agreement. It may be noted that the present data are generally different with experimental data, since the available data are extrapolated to high Grashof number. Thus the deviation may be large with present data.

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Olsen, Nils Reidar B., et Stefan Haun. « Numerical modelling of bank failures during reservoir draw-down ». E3S Web of Conferences 40 (2018) : 03001. http://dx.doi.org/10.1051/e3sconf/20184003001.

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Numerical algorithms are presented for modeling bank failures during reservoir flushing. The algorithms are based on geotechnical theory and the limit equilibrium approach to find the location and the depth of the slides. The actual movements of the slides are based on the solution of the Navier-Stokes equations for laminar flow with high viscosity. The models are implemented in the SSIIM computer program, which also can be used for modelling erosion of sediments from reservoirs. The bank failure algorithms are tested on the Bodendorf hydropower reservoir in Austria. Comparisons with measurements show that the resulting slides were in the same order of magnitude as the observed ones. However, some scatter on the locations were observed. The algorithms were stable for thick sediment layers, but instabilities were observed for thin sediment layers.

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BILIAIEV, M. M., O. V. BERLOV, V. V. BILIAIEVA, V. A. KOZACHYNA et T. I. RUSAKOVA. « NUMERICAL MODELING OF AIR POLLUTION NEAR THE HIGHWAY WITH PROTECTIVE BARRIERS ». Ukrainian Journal of Civil Engineering and Architecture, n^o 2 (9 juillet 2022) : 7–14. http://dx.doi.org/10.30838/j.bpsacea.2312.260422.7.846.

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Problem statement. The problem of predicting chemical pollution zones near the highway, where protective barriers are located, is considered. The protective barriers influence the aerodynamics of air flow and reduce the level of working areas chemical pollution near the highway. It is necessary to have mathematical models that allow such evaluation at the design stage in order to evaluate the effectiveness of protective barriers promptly. The purpose of the article. Development of a numerical multi-parameter model and computer program for evaluating the effectiveness of the protective barriers using near the highway to reduce the chemical contamination level of work areas. Methodology. A two-dimensional mass transfer equation is used for mathematical modeling of chemical hazardous substances spreading that are emitted from a car and spread near the highway. This simulation equation takes into account the wind direction, atmospheric diffusion, the intensity of chemically hazardous substance emission from the car, the emission source location, the car body and the location of protective barriers near the highway. The Navier − Stokes equation and the potential motion model both are used to solve the aerodynamics problem of determining the uneven air velocity field near the highway. An implicit splitting difference scheme is used to numerically integrate the vortex transfer equation. Two numerical schemes are used to numerically integrate the equation for the current function. An explicit difference scheme is used to numerically integrate the Laplace equation for the velocity potential. Based on the constructed numerical model the package of programs is developed. To solve numerically equation of pollutant transfer the finite difference schemes of splitting are used. Scientific novelty. To calculate the formation of chemical pollution areas for atmospheric air near the highway during emissions from vehicles numerical model is proposed. This model allow to estimate the protective barriers effectiveness for reducing air pollution in the working areas. Practical significance. Based on the developed model the code for quickly calculation of air pollution process both near the highway and in work areas protecting with barriers is created. Conclusions. The developed numerical model and the computer code implementing it allow to investigate the process of chemical hazardous substance spreading in the atmospheric air near the highway. The model allows to quickly determine the effectiveness of protective barriers using near the highway. The developed computer program can be implemented on low and medium power computers. The results of a computational experiment are presented.

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Teleszewski, Tomasz Janusz. « Effect of viscous dissipation in stokes flow between rotating cylinders using BEM ». International Journal of Numerical Methods for Heat & ; Fluid Flow 30, n^o 4 (20 mai 2019) : 2121–36. http://dx.doi.org/10.1108/hff-11-2018-0622.

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Purpose The purpose of this paper is to apply the boundary element method (BEM) to Stokes flow between eccentric rotating cylinders, considering the case when viscous dissipation plays a significant role and determining the Nusselt number as a function of cylinder geometry parameters. Design/methodology/approach The problem is described by the equation of motion of Stokes flow and an energy equation with a viscous dissipation term. First, the velocity field and the viscous dissipation term were determined from the momentum equation. The determined dissipation of energy and the constant temperature on the cylinder walls are the conditions for the energy equation, from which the temperature distribution and the heat flux at the boundary of the cylinders are determined. Numerical calculations were performed using the author’s own computer program based on BEM. Verification of the model was carried out by comparing the temperature determined by the BEM with the known theoretical solution for the temperature distribution between two rotating concentric cylinders. Findings As the ratio of the inner cylinder diameter to the outer cylinder diameter (r1/r2) increases, the Nusselt number increases. The angle of inclination of the function of the Nusselt number versus r1/r2 increases as the distance between the centers of the inner and outer cylinders increases. Originality/value The computational results may be used for the design of slide bearings and viscometers for viscosity testing of liquids with high viscosity where viscous dissipation is important. In the work, new integral kernels were determined for BEM needed to determine the viscous dissipation component.

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Bahatmaka, Aldias, Dong-Joon Kim et Samsudin Anis. « A Validation Simulation using OpenFOAM : Nozzle Length and Angle Effect on the Ducted Propeller Performance ». IOP Conference Series : Earth and Environmental Science 1083, n^o 1 (1 septembre 2022) : 012088. http://dx.doi.org/10.1088/1755-1315/1083/1/012088.

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Abstract The use of numerical simulation is needed for predicting the performance of the ship. The Computational Fluid Dynamics (CFD) method is based on the improvement of Reynold-Average Navier Stokes (RANS) equation, in order to compute the simulation for solving the engineering problem. The simulation was begun by conducting several calculations to validate the numerical method applied in open water propeller test. A Kaplan type propeller is selected with 19A nozzle. The Moving Rotating Frame (MRF) method was selected to test the ducted propeller performance by modifying the nozzle length and angle. The model was designed in Computer-Aided Design (CAD) program and predicted the performance using the OpenFOAM. The OpenFOAM was used as open source CFD tool. The results are validated by comparing with experimental value of J from 0.2 to 0.8 and produced the thrust, torque and efficiency trends in good agreement with experimental data. Due to the results, can be conclude that by increasing the nozzle length to 10% and 20%, the thrust was decreased about 2.25% and 3.01% at low advance coefficient to 7.06% and 9.41% at high advance coefficient. By increasing the nozzle angle, both thrust and torque were increased while efficiency decreased especially at low coefficient.

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Vianna, Rafael S., Alexsander M. Cunha, Rodrigo B. V. Azeredo, Ricardo Leiderman et Andre Pereira. « Computing Effective Permeability of Porous Media with FEM and Micro-CT : An Educational Approach ». Fluids 5, n^o 1 (24 janvier 2020) : 16. http://dx.doi.org/10.3390/fluids5010016.

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Permeability is a parameter that measures the resistance that fluid faces when flowing through a porous medium. Usually, this parameter is determined in routine laboratory tests by applying Darcy’s law. Those tests can be complex and time-demanding, and they do not offer a deep understanding of the material internal microstructure. Currently, with the development of new computational technologies, it is possible to simulate fluid flow experiments in computational labs. Determining permeability with this strategy implies solving a homogenization problem, where the determination of the macro parameter relies on the simulation of a fluid flowing through channels created by connected pores present in the material’s internal microstructure. This is a powerful example of the application of fluid mechanics to solve important industrial problems (e.g., material characterization), in which the students can learn basic concepts of fluid flow while practicing the implementation of computer simulations. In addition, it gives the students a concrete opportunity to work with a problem that associates two different scales. In this work, we present an educational code to compute absolute permeability of heterogeneous materials. The program simulates a Stokes flow in the porous media modeled with periodic boundary conditions using finite elements. Lastly, the permeability of a real sample of sandstone, modeled by microcomputed tomography (micro-CT), is obtained.

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Siow, C. L., Jaswar et Efi Afrizal. « Computational Fluid Dynamic Using Parallel Loop of Multi-Cores Processor ». Applied Mechanics and Materials 493 (janvier 2014) : 80–85. http://dx.doi.org/10.4028/www.scientific.net/amm.493.80.

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Computational Fluid Dynamics (CFD) software is often used to study fluid flow and structures motion in fluids. The CFD normally requires large size of arrays and computer memory and then caused long execution time. However, Innovation of computer hardware such as multi-cores processor provides an alternative solution to improve this programming performance. This paper discussed loop parallelize multi-cores processor for optimization of sequential looping CFD code. This loop parallelize CFD was achieved by applying multi-tasking or multi-threading code into the original CFD code which was developed by one of the authors. The CFD code was developed based on Reynolds Average Navier-Stokes (RANS) method. The new CFD code program was developed using Microsoft Visual Basic (VB) programming language. In the early stage, the whole CFD code was constructed in a sequential flow before it is modified to parallel flow by using VBs multi-threading library. In the comparison, fluid flow around the hull of round-shaped FPSO was selected to compare the performance of both the programming codes. Besides, executed results of this self-developed code such as pressure distribution around the hull were also presented in this paper.

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Sakim, Anas, Mohamed Nabhani et Mohamed El Khlifi. « Viscous shear effect in non-Newtonian lubrication of finite porous elastic bearings ». Industrial Lubrication and Tribology 71, n^o 3 (8 avril 2019) : 374–80. http://dx.doi.org/10.1108/ilt-07-2018-0292.

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Purpose The purpose of this study is to investigate the viscous shear effect on finite porous elastic journal bearings lubricated with non-Newtonian couple stress fluid. Design/methodology/approach Based on Stokes micro-continuum mechanics, the modified Reynolds equation including bearing deformation was derived. The porous flow was modeled by the complete Darcy–Brinkman equation. To show the viscous shear effects, bearing characteristics including load capacity and friction factor are compared to those obtained from Darcy model with Beavers–Joseph slip conditions (slip flow model [SFM]) by developing a computer program and discussed for different couple stress values, permeabilities and elastic deformation parameters. Findings It is found that the viscous shearing forces effects of the Brinkman model increase the load capacity and friction factor compared to those derived using SFM. Moreover, the couple stresses increase the load capacity while decreasing the friction factor for both models. Originality/value This study introduces for the first time the viscous effect on finite porous elastic journal bearings lubricated with couple stress fluid.

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Amosov, Pavel V. « ON THE RELIABILITY OF THE ASSESSMENT OF THE THERMAL MODE OF AN UNDERGROUND SPENT NUCLEAR FUEL STORAGE FACILITY BASED ON NUMERICAL MODELING ». Bulletin of the Saint Petersburg State Institute of Technology (Technical University) 62 (2022) : 84–90. http://dx.doi.org/10.36807/1998-9849-2022-62-88-84-90.

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The results of checking the reliability of a previously performed assessment of the thermal mode of an underground facility for long-term storage of spent nuclear fuel in a variant of an integrated reinforced concrete structure on three calculation grids (Coarse, Normal, Fine) are presented. The test was performed on a previously developed three-dimensional computer model in the COMSOL program. The mathematical basis of the model is following: continuity equation, Navier-Stokes equations averaged by Reynolds, standard turbulence model and general heat transfer equation. The consideration of mixed convection conditions was implemented in the "incompressible ideal gas" approximation. It was shown that when using computational grids with high resolution (Normal, Fine), some characteristics may be predicted. They are: temperature increase inside the built-in structure and at the boundary "rock mass - built-in structure" no more than 1°C; a significant change in the structure of the spatial distribution of temperature and an increase in maximum temperatures by about 1°C on the surface of the built-in structure. The duration of calculations in variants with small grids increased approximately 3.4 (Normal) and 7.7 (Fine) times, respectively

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Wang, Yazhou, Guoliang Qin, Ximeng Ye et Zhenzhong Bao. « SEM-based numerical framework for non-Darcy mixed convection in a porous cavity with three adiabatic thin baffles on the hot wall ». International Journal of Numerical Methods for Heat & ; Fluid Flow 29, n^o 9 (2 septembre 2019) : 3366–93. http://dx.doi.org/10.1108/hff-12-2018-0820.

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Purpose The purpose of this paper is to develop a numerical framework based on the accurate spectral element method (SEM) to simulate the mixed convective heat transfer within a porous enclosure with three adiabatic thin baffles of different lengths in nine cases and analyze the effects of several parameters. Design/methodology/approach The authors develop an improved time-splitting method to solve the Darcy–Brinkman–Forchheimer model. No extra assumptions are introduced for the intermediate velocity, and the final velocity field satisfies the incompressible constraint strictly compared with the classical method. The governing equations are split into a pure convection problem, a Stokes problem and a thermal diffusion problem. The least-squares variation is adopted for the Stokes problem, and the Galerkin variation is used for the other two problems, such that the pressure and velocity can be discretized with the same interpolation order, which benefits the numerical accuracy and program design. Findings Regarding the method, the excellent spectral accuracy, the capability of discretizing complex computational regions and the improved time-splitting methods make SEM an effective tool to accurately predict the non-Darcy convective heat transfer; as for the numerical tests, it is observed that weakened convection and heat transfer are induced by the increasing length of the baffles. The flow and heat transfer in channel 1 is only related to the length of baffle 1 because of the downward-driven right sidewall, and it is more difficult for baffle 3 to form the secondary flow on its tip. Originality/value A novel numerical framework for Darcy–Brinkman–Forchheimer model is developed, expanding the application of SEM for simulating non-Darcy convective heat transfer to improve the numerical accuracy. Numerical results and analysis for flow and heat fields could help designers understand the control of heat transfer using adiabatic baffles better.

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Hong, Keyyong, Sun-Young Kim et Museok Song. « A REAL-TIME SIMULATION OF THE TRAJECTORY AND FATE OF SPILLED OIL AT SEA ». International Oil Spill Conference Proceedings 1997, n^o 1 (1 avril 1997) : 573–77. http://dx.doi.org/10.7901/2169-3358-1997-1-573.

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ABSTRACT On the basis of the physical modeling of the trajectory and fate of spilled oil at sea, an integrated computer program was developed for the real-time prediction of spilled oil behavior. The trajectory model describes the movement of the surface spill center of mass, and the trajectory is mainly governed by the velocity of the wind and the surface current. For the fate model, weathering effects of spreading, evaporation, emulsification, and shoreline interaction are included. The Windows-based GUI has a flexible preprocessor that enables one to use measured field data as well as numerically generated data. For the realtime prediction, environmental data are stored in the database. The database on tidal and oceanic currents is produced by solving a Navier-Stokes equation based on the IAF finite difference method. The measured data are used for both the boundary condition of the governing equation and the calibration of the generated current field. An oil spill accident in the south coastal region of Korea is simulated and compared with the observed data. The simulation result indicates that the developed oil spill model gives a reasonable estimation of the route of spilled oil. Further improvement of the environmental database is required for the accurate prediction of spilled oil behavior.

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TSVETKOVA, NADEZHDA V., et EVGENIA I. SLUCHANKO. « COMPUTER SIMULATION OF ATHEROSCLEROTIC PROCESS INFLUENCE IN THE INTERNAL CAROTID ARTERY ON THE HEMODYNAMICS OF BRACHIOCEPHAL ARTERIES AND THE CIRCLE OF WILLISIAN ». Bulletin of Contemporary Clinical Medicine 15, n^o 5 (octobre 2022) : 73–80. http://dx.doi.org/10.20969/vskm.2022.15(5).73-80.

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Abstract. Introduction. The wide prevalence of atherosclerosis, as the main cause of the pathology of the cardiovascular system, determines its medical and social significance. Currently, the diagnosis of atherosclerosis is carried out by Doppler ultrasound and radiopaque CT- angiography. However, the most promising direction in the diagnosis of atherosclerosis is the creation and implementation in clinical practice of simulation computer models of the atherosclerotic process. Aim. The aim is to develop a simulation computer model of brachiocephalic arteries with the circle of Willis in normal conditions and with atherosclerotic changes in the vascular wall for the diagnosis and early prediction of the development of vascular complications. Material and methods. Data of X-ray contrast CT angiography of brachiocephalic arteries and ultrasound Dopplerography of neck vessels 4 patients with varying degrees of stenosis were used in the work. A computer model of the atherosclerotic process in the brachiocephalic arteries and arteries of the circle of Willis was built in the Comsol Multiphysics program using the finite element method to calculate the quantitative characteristics of blood. A mathematical model has been developed for the movement of fluids in blood vessel (Navier-Stokes equation, continuity equation, equilibrium equation). Results and discussion. Based on the developed simulation model of the atherosclerotic process, an application focused on medical workers has been created. The functionality of this application allows the user to adjust the geometry parameters (size, number and location of atherosclerotic plaques in the vessels) and the blood flow rate in accordance with the requirements of the study. With this application, the user can create a personalized model for the study of patients with cardiovascular pathology. Conclusion. The created computer model of brachiocephalic arteries with the circle of Willis and the application developed on its basis can be used in clinical practice as an additional in support of other imaging methods method for diagnosing atherosclerosis and early prediction of its complications, as well as for studying the pathogenetic role of the atherosclerotic process in patients with cardiovascular pathology.

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Sakulchangsatjatai, P., N. Thuchayapong, P. Terdtoon et N. Sangsirakoup. « Effect of Tube Bending on Heat Transfer Characteristics of Miniature Heat Pipe with Sintered Porous Media ». Defect and Diffusion Forum 312-315 (avril 2011) : 1015–20. http://dx.doi.org/10.4028/www.scientific.net/ddf.312-315.1015.

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Miniature heat pipe is a compact heat transfer device with very high heat transfer capability. The miniature heat pipes have been widely accepted for thermal management in laptop computer. Generating heat from chip-set is rapidly transferred to a heat sink via the miniature heat pipe which occupies small space, resulting in smaller and more attractive size of the laptop. Heat pipe bending is unavoidable in such small space. However, tube bending decreases thermal performance of heat pipe and it stops working in some cases. In this study, a computer program to simulate heat transfer characteristics of a bending water-copper-sintered-wick heat pipe has been established. Domains of heat pipe consist of three parts; vapor of working fluid in vapor core which transfer heat and mass from evaporator section to condenser section, liquid of working fluid in wick which transfer heat and mass from condenser section to evaporator section in porous media by capillary force, and container wall. In simulation, fluid flow and heat transfer were assumed to be steady, laminar and incompressible. The porous media is saturated with liquid and working fluid is assumed to be Newtonian fluid. The governing equations, i.e. continuity, Navier-Stokes, and energy equations, and boundary conditions were solved by using the Finite Element Method (FEM). Several bending angles (0 and 90; angle measured from straight pipe) with 6 mm outer diameter and 200 mm length were simulated and tested. It was found that the predicted and experimental thermal resistances of heat pipe, when bending angle increases from 0 to 90, increased from 0.47°C/W to 0.65°C/W and 0.67°C/W to 0.88°C/W respectively, due to rising of the vapor pressure drop in vapor channel. The simulation results are in agreement with experimental data with 26-29% error.

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Drešar, Primož, et Jožef Duhovnik. « A Hybrid RANS-LES Computational Fluid Dynamics Simulation of an FDA Medical device benchmark ». Mechanics 25, n^o 4 (28 août 2019) : 291–98. http://dx.doi.org/10.5755/j01.mech.25.4.20105.

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Computational fluid dynamics (CFD) is a valuable tool that complements experimental data in the development of medical devices. The reliability of CFD still presents an issue and for that reason, no standardized approaches are currently available. The United States Food and Drug Administration (FDA) has initiated the development of a program for CFD validation, and has presented an idealized nozzle benchmark model. In this study, a nozzle flow with sudden expansion has been simulated using advanced RANS-LES turbulence models. Such models partially resolve the flow and are cheaper in computer resources and time in comparison to the Large Eddy Simulation (LES). Furthermore, they are more accurate than standard Reynolds-averaged Navier-Stokes (RANS) models. A collection of hybrid turbulence models has been investigated: Detached Eddy Simulation (DES), Stress Blended Eddy Simulation (SBES), and Scale Adaptive Simulation (SAS), and compared to a standard RANS Shear Stress Transport (SST) model. Subsequently, all models were validated by experimental results already published by different research groups. Particle Image Velociometry (PIV) experiments were performed by inter-laboratory study, and the results are available online for numerical validation. The flow conditions in this study are only restricted to a turbulence flow at a Reynolds number of Re =6500. Complementing the turbulence models investigation, two advection schemes were tested: high resolution (HR) and bounded central difference scheme (BCD). Among all advanced models the SBES model with BCD scheme has the best agreement with the experimental values.

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Al-Hafidh, Manal Hadi, et Lina S. Safwat. « MIXED CONVECTIVE AND RADIATIVE HEAT TRANSFER IN A HORIZONTAL CONCENTRIC AND ECCENTRIC CYLINDRICAL ANNULI ». Journal of Engineering 18, n^o 05 (19 juin 2023) : 552–70. http://dx.doi.org/10.31026/j.eng.2012.05.03.

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A numerical investigation has been performed to study the effect of eccentricity on unsteady state, laminar aiding mixed convection in a horizontal concentric and eccentric cylindrical annulus. The outer cylinder was kept at a constant temperaturewhile the inner cylinder was heated with constant heat flux. The study involved numerical solution of transient momentum (Navier-Stokes) and energy equation using finite difference method (FDM), where the body fitted coordinate system (BFC) wasused to generate the grid mesh for computational plane. The governing equations were transformed to the vorticity-stream function formula as for momentum equations and to the temperature and stream function for energy equation.A computer program (Fortran 90) was built to calculate the bulk Nusselt number (Nub) after reaching steady state condition for fluid Prandtl number fixed at 0.7 (air) with radius ratio ( =2.6), Rayleigh number (Ra=200), Reynolds number (Re=50) for both concentric and eccentric cylindrical annulus with different eccentricity ratios (ε=0, 0.25, 0.50, 0.75) and angular positions (φo=0o, 45o , 90o , 135o , 180o ).The results show a reasonable representation to the relation between Nusselt number and (ε, φo). Generally, Nub decreased with the increase in (ε and φo). Also, results show that the best thermal performance for the inner cylinder was at the angularposition (φo=0o ) for eccentricity ratio (ε=0.25), while the maximum reduction in the rate of heat transfer for the inner cylinder was at the angular position (φo=180o) for eccentricity ratio (ε=0.75).Comparison of the result with the previous work shows a good agreement.

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Shnal, T., S. Pozdieiev, R. Yakovchuk, O. Nekora et S. Sidnei. « MATHEMATICAL MODELING OF FIRE DEVELOPMENT IN A THREE-STOREY RESIDENTIAL BUILDING DURING FULL-SCALE FIRE TESTS ». Fire Safety 36 (23 juillet 2020) : 121–30. http://dx.doi.org/10.32447/20786662.36.2020.14.

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The aim of the work was mathematical modeling of fire development in a three-storey residential building during full-scale fire tests; research of accuracy and reliability of parameters of temperature modes of fire in separate rooms of the building. To achieve this goal, it is advisable to use computational gas-hydrodynamics, which allow to determine the limits of application of this approach to predict the behavior of building structures in a fire. The Pyrosim computer system, which serves as a user shell for the Fire Dynamics Simulator program, was used to calculate the temperature in fire room models. This FDS system uses numerical algorithms to solve the complete system of Navier-Stokes differential equations to determine temperature and other hazards in a fire. To visualize the results of calculations, the software module of the PyroSim Smokeview system was used, which allows to build appropriate graphical representations of temperature distributions.A numerical experiment was performed to model full-scale tests of rooms with fire in a three-story building using computer gas-hydrodynamics methods. The nature of the fire and the time dependences of its main parameters were revealed, which in turn allowed to analyze the adequacy of the simulation results and investigate their adequacy and accuracy.The obtained results of research on the accuracy of modeling of full-scale tests of rooms with fire in a three-story building showed that the error determined when comparing experimental and calculated data was not significant. The relative error did not exceed 28%, and the standard deviation did not exceed 51 ° C. The values of the statistical criteria of Cochren, Student and Fisher for the simulation results due to the difference between the calculated and experimental data have values of no more than 0.98, 0.84 and 1.008, respectively, and do not exceed the tabular values. This means that the simulation results are adequate, which allows you to use this approach to predict the behavior of building structures in a fire that is close to real.

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Rüther, Nils, Jens Jacobsen, Nils Reidar B. Olsen et Geir Vatne. « Prediction of the three-dimensional flow field and bed shear stresses in a regulated river in mid-Norway ». Hydrology Research 41, n^o 2 (1 février 2010) : 145–52. http://dx.doi.org/10.2166/nh.2010.064.

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This study evaluates the use of two Computational Fluid Dynamics (CFD) techniques in calculating the three-dimensional flow and bed shear stress distribution in a regulated river reach near Trondheim, Norway. The two different CFD codes being used in this study are: one commercial FLOW-3D and an in-house program, SSIIM, developed by the third author (NRBO). One of the primary differences between the programs is that FLOW-3D uses an orthogonal, structured grid, while SSIIM uses a non-orthogonal unstructured grid. Flow-3D computes the location of the free water surface based on a volume of fluid method. In the current study, the water surface profile was computed using a 1D backwater computation with SSIIM. Both programs use first- or second-order schemes for the convective term in the Navier–Stokes equations, and the study investigated both options for the two different models. The computed results were compared to ADCP measurements obtained from three cross sections of the river. The comparison showed a good agreement between calculated and measured velocities when using higher-order discretization schemes. Using a first-order upwind scheme, the results deteriorated somewhat due to false diffusion. The results of this current study could be beneficial for the estimation of fluvial erosion, which causes severe damages to riverine areas.

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Khalil Khudhair, Baydaa, et Adel Mahmood Salh. « THE EFFECT OF VIBRATION ON NATURAL CONVECTION HEAT TRANSFER IN AN ENCLOSED SQUARE CAVITY ». IRAQI JOURNAL FOR MECHANICAL AND MATERIALS ENGINEERING 20, n^o 4 (28 décembre 2020) : 282–307. http://dx.doi.org/10.32852/iqjfmme.v20i4.525.

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A numerical investigation has been implemented to elucidate the effect of vertical and horizontal vibration at normal gravity on natural convection in a square enclosure filled with air at Rayleigh number 7×107 and 4× 108. The enclosure was comprised of two vertical and opposed surfaces (the right hot and the left cold) while the two other surfaces are adiabatic. The two-dimensional, low-Reynolds number k ? ???? turbulence model is applied to enable it to cope with low Reynolds number flows. By transforming the equation of (continuity, Navier-Stokes and energy) using finite volume method from differential forms to algebraic forms using SIMPLE algorithm with hybrid scheme dealing with the time term are adopted to solve the governing equations. A computer program in Fortran 90 was built to carry on the numerical solution. Three cases were studied in this work, case I(reaches to steady state and then begins the effect of vibration at each frequency), caseII and caseIII(begin the effect of vibration from the transient at ascending and descending frequencies respectively).After the validity of the present code by comparing results with these of previous study for similar conditions, solutions have been obtained for Prandtle number of 0.7, aspect ratio (A=1). In the high Rayleih number case (Ra=4×108), the gravitional thermal convection dominates, and the vibration motion does not enhances the heat transfer remarkably. In contrast, in low Rayleigh (Ra=7×107), the vibration thermal convection is dominant, and the vibration enhaces the heat transfer rate significantly. The effect of vertical directional vibration is more powerful in caseII(ascending frequency), when the horizontal directional vibration more effective in case III(descending frequency).

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Zhang, Liang Dong, Ying Hua Liao et Chun Hua Fu. « Development of Computer-Aided Design Module for Mechanical Products Based on AutoCAD ». Advanced Materials Research 842 (novembre 2013) : 691–94. http://dx.doi.org/10.4028/www.scientific.net/amr.842.691.

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Based on the basic process of mechanical product design and a modular design idea, the module includes three parts, i.e. design calculation, computer-aided drawing and foundation database. The design calculation mainly includes the commonly used design calculation program in mechanical product design, and the computer-aided drawing mainly includes the parametric drawing programs about the drawing environment and the commonly used machine parts, the foundation database mainly stores the data related to the mechanical product design. Then a computer-aided design module for mechanical product will be constructed by Autolisp and DCL. And the proposed computer-aided design module is developed on the friendly interface, easy to use, and can provide mechanical engineers for product design efficiency greatly.

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Deissler, Robert J., Rose Al Helo et Robert Brown. « From an obliquely falling rod in a viscous fluid to the motion of suspended magnetic bead chains that are driven by a gradient magnetic field and that make an arbitrary angle with the magnetic force vector : A Stokes flow study ». PLOS ONE 19, n^o 4 (16 avril 2024) : e0301852. http://dx.doi.org/10.1371/journal.pone.0301852.

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In view of the growing role of magnetic particles under magnetic field influence in medical and other applications, and perforce the bead chaining, it is important to understand more generally the chain dynamics. As is well known, in the presence of a magnetic field, magnetic beads tend to form chains that are aligned with the magnetic field vector. In addition, if there is a magnetic field gradient, there will be a magnetic force acting on this chain. The main goal of the present research is to study the motion of a magnetic bead chain that makes an arbitrary angle with the magnetic force vector in the Stokes flow limit, that is, in the limit of zero Reynolds number. We used the public-domain computer program HYDRO++ to calculate the mobility matrix, which relates the magnetic force acting on the chain to the velocity of the chain, for a chain of N beads making an arbitrary angle with the magnetic force vector. Because of the presence of off-diagonal elements of the mobility matrix, as the chain is drawn in the direction of the magnetic force, it is also deflected to the side. We derived analytic solutions for this motion. Also, for bead chains moving in directions both parallel and perpendicular to their lengths, we fit three-parameter functions to solutions from HYDRO++. We found the fits to be excellent. Combining these results with the analytic solutions, we obtained expressions for the velocity components for the bead chains that provide excellent fits to HYDRO++ solutions for arbitrary angles. Finally, we apply the methodology used for the bead chain studies to the study of an obliquely falling rod in a viscous fluid and derive analytic solutions for the velocity components of the obliquely falling rod.

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Michalski, Jacek, et Jacek Domański. « Macroscopic model for honing motor cylinders exhaust as a tool optimizing height smooth gasket in repair technology ». AUTOBUSY – Technika, Eksploatacja, Systemy Transportowe 19, n^o 6 (30 juin 2018) : 600–608. http://dx.doi.org/10.24136/atest.2018.142.

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The paper presents the assumptions of the macroscopic mathematical model of honing, taking into account both the kinematics of the tool and the characteristic for this process the distribution of unit pressures occurring in the interaction of sharpening stones on the surface of the honing stones on the surface of the workpiece are characteristic for this process. On the basis of these assemblies an active and tested computer program has been developed, which numerically model this technological process. In the computer memory are created digital quality maps of the surface of the machined cylinder. On the basis of the described assemblies, a working and tested computer program has been developed that numerically models this technological process. Digital quality maps are created in the computer's memory regarding the surface of both the cylinder and the smoothing stones. These maps can be assessed analytically as well as subjected to visualization. The article presents the results of calculations that optimize the height of smooth ground for the process of honing a specific cylinder liner with the analysis of the results ob-tained. The described computer program saves time and funds during dedicated research that optimizes the pa-rameters of this process

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Ozdemir, Sahika, et Hakan TONG. « A Model Proposal for Store Design with Shape Grammar ». Asian Journal of Interdisciplinary Research 3, n^o 1 (11 mars 2020) : 196–205. http://dx.doi.org/10.34256/ajir20115.

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With the widespread use of computers, rule-based design methods that can work in harmony with computer logic and can be easily adapted to the computer environment have come to the forefront in the design world. To be able to analyze the logic of a design made with the shape grammar method which is one of the rule based design methods; it is even possible to modify and transform the design, which has been placed on the rule base by removing shape rules, or to create new designs with the same design logic. In this study, some stores that will be exemplary for the store design are examined, analyzed and the system is designed to produce new plan schemes. In this study, it is aimed to produce a program that offers abstract plan alternatives to the designer during the early design process. In store design, clothing stores are emphasized especially due to its intensive use. Within the scope of the study, it is focused on developing a program that produces plan alternatives by using computational power of computer. In this way, it was possible to work on many plan alternatives in a short time during the design process and it became easy to examine large areas. With these alternatives, it is aimed to provide rapid and advance detection of possible problems that may arise. At this point, it is aimed to see a large number of plan alternatives by applying a few rules and to make the appropriate selection among these alternatives.

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Silver, David, Richard Sutton et Martin Mueller. « Temporal-Difference Search in Computer Go ». Proceedings of the International Conference on Automated Planning and Scheduling 23 (2 juin 2013) : 486–87. http://dx.doi.org/10.1609/icaps.v23i1.13578.

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Temporal-difference (TD) learning is one of the most successful and broadly applied solutions to the reinforcement learning problem; it has been used to achieve master-level play in chess, checkers and backgammon. Monte-Carlo tree search is a recent algorithm for simulation-based search, which has been used to achieve master-level play in Go. We have introduced a new approach to high-performance planning. Our method, TD search, combines TD learning with simulation-based search. Like Monte-Carlo tree search, value estimates are updated by learning online from simulated experience. Like TD learning, it uses value function approximation and bootstrapping to efficiently generalise between related states. We applied TD search to the game of 9x9 Go, using a million binary features matching simple patterns of stones. Without any explicit search tree, our approach outperformed a vanilla Monte-Carlo tree search with the same number of simulations. When combined with a simple alpha-beta search, our program also outperformed all traditional (pre-Monte-Carlo) search and machine learning programs on the 9x9 Computer Go Server.

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Kratzert, Daniel, et Ingo Krossing. « StructureFinder ». Journal of Applied Crystallography 52, n^o 2 (14 février 2019) : 468–71. http://dx.doi.org/10.1107/s1600576719001638.

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With the program StructureFinder it is possible to find single-crystal diffraction measurements stored in any location on a computer. StructureFinder collects the unit-cell information and other data from previous measurements and stores them in a database. Searching is performed via a graphical user interface, and both a stand-alone program and a web interface are available.

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SARMENTO, C. V. S., A. O. C. FONTE, L. J. PEDROSO et P. M. V. RIBEIRO. « From numerical prototypes to real models : a progressive study of aerodynamic parameters of nonconventional concrete structures with Computational Fluid Dynamics ». Revista IBRACON de Estruturas e Materiais 13, n^o 3 (juin 2020) : 628–43. http://dx.doi.org/10.1590/s1983-41952020000300012.

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Abstract The practical evaluation of aerodynamic coefficients in unconventional concrete structures requires specific studies, which are small-scale models evaluated in wind tunnels. Sophisticated facilities and special sensors are needed, and the tendency is for modern and slender constructions to arise with specific demands on their interaction with the wind. On the other hand, the advances obtained in modern multi-core processors emerge as an alternative for the construction of sophisticated computational models, where the Navier-Stokes differential equations are solved for fluid flow using numerical methods. Computations of this kind require specialized theoretical knowledge, efficient computer programs, and high-performance computers for large-scale calculations. This paper presents recent results involving two real-world applications in concrete structures, where the aerodynamic parameters were estimated with the aid of computational fluid dynamics. Conventional quad-core computers were applied in simulations with the Finite Volume Method and a progressive methodology is presented, highlighting the main aspects of the simulation and allowing its generalization to other types of problems. The results confirm that the proposed methodology is promising in terms of computational cost, drag coefficient estimation and versatility of simulation parameters. These results also indicate that mid-performance computers can be applied for preliminary studies of aerodynamic parameters in design offices.

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Steensgaard, Bjarne. « Sparse functional stores for imperative programs ». ACM SIGPLAN Notices 30, n^o 3 (mars 1995) : 62–70. http://dx.doi.org/10.1145/202530.202536.

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Serik, M., G. Nurbekova et J. Kultan. « Big data technology in education ». Bulletin of the Karaganda University. Pedagogy series 100, n^o 4 (28 décembre 2020) : 8–15. http://dx.doi.org/10.31489/2020ped4/8-15.

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The article discusses the implementation of big data in the educational process of higher education. The authors, analyzing a large amount of data, referring to the types of services provided by e-government, indicate that there are many pressing problems, many services are not yet automated. In order to improve the professional training of teachers of Computer Science of the L.N. Gumilyov Eurasian National University, educational programs and courses have been developed 7M01514 — «Smart City technologies», «Big Data and cloud computing» and 7М01525 — «STEM-Education», «The Internet of Things and Intelligent Systems «on the theoretical and practical foundations of big data and introduced into the educational process. The arti-cle discusses several types of programs for teaching big data and analyzes data on the implementation of big data in some educational institutions. For the introduction and implementation of special courses in the educational process in the areas of magistracy in the educational program Computer Science, the curriculum, educational and methodological complex, digital educational resources are considered, as well as hardware and software that collects, stores, sorts big data, well as the introduction into the educational process of theoretical foundations and methods of using the developed technical and technological equipment.

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Mališ, Tanja, Petar Hrženjak, Antonia Jaguljnjak Lazarević et Mislav Mikulec. « APPLICATION OF THE SAP2000 COMPUTER PROGRAMME IN THE MODELLING OF AN UNDERGROUND QUARRY OF DIMENSION STONE ». Rudarsko-geološko-naftni zbornik 38, n^o 4 (2023) : 19–25. http://dx.doi.org/10.17794/rgn.2023.4.2.

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A numerical analysis of part of the underground quarry of dimension stone with designed maximum dimensions of the rooms was carried out with the SAP2000 software based on the finite element method. The main objective of the analysis was to examine the preliminary stability and the influence of excavation on the redistribution of stresses in the surrounding rock masses, thus confirming the applicability of the tributary area method. The analytical solution with the tributary area method showed satisfactory agreement with the numerical calculations, and the results of the analytical calculations were on the safe side. The obtained results confirmed the predicted behaviour of the rock mass, which confirms the use of SAP2000 as a general-purpose software for civil engineering in the field of mining. The highest concentrations of stresses and strains are found in the edge areas of the pillars, so their correct design is crucial. The safety factor of the point with the highest stresses was determined and a value of 2.21 was obtained, thus fulfilling the stability condition. As for the influence on the surrounding area, stress changes of less than 10% were determined based on the solutions for the vertical stresses at a distance of 20 m from the underground excavation.

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Ahenkora, Samuel, Emmanuel Boakye Adubofour, Emmanuel Gyimah Osei et Aminatu Ibrahim. « Technology Use Among Ghanaian Junior High School Mathematics Teachers in the Ahafo – Ano South District ». Journal of Education and Training Studies 11, n^o 3 (3 juin 2023) : 78. http://dx.doi.org/10.11114/jets.v11i3.6066.

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The study sought to investigate technology use among Ghanaian Junior High School mathematics teachers in the Ahafo-Ano South District of Ghana. Descriptive survey (cross-sectional survey) design with mixed quantitative and qualitative data was gathered for the study. The population of the study comprised of all JHS mathematics teachers in Ahafo-Ano South District, Ashanti region. A stratified sampling technique was used to select 60 JHS mathematics teachers from rural, peri-urban and urban schools in the district. The findings revealed that mathematics teachers technology use in teaching Mathematics at the Junior High School level in the district was low (2.048 ± .85388). These technologies were grouped into manipulatives, digital/computer-based and audio-visual technologies. The results established that most of the teachers used manipulates in teaching Mathematics (3.120 ± 1.063). On the contrary, the results also showed that digital/computer-based technologies such as virtual protractors, calculators, geometry pad, stepping stones 2.0 comprehensive mathematics and computer game programs such as Globaloria etc., were never used by mathematics teachers in the district (1.621 ± .840). Similarly, evidence from the study adds that audio-visual technologies including television, pie chart assignment to students based on TV program and other audio-visual devices were never in use by mathematics teachers in the district (1.416 ± .712).

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BLINKOV, Yu A., et A. Yu REBRINA. « INVESTIGATION OF DIFFERENCE SCHEMES FOR TWO-DIMENSIONAL NAVIER-STOKES EQUATIONS BY USING COMPUTER ALGEBRA ALGORITHMS ». Программирование, n^o 1 (1 janvier 2023) : 32–37. http://dx.doi.org/10.31857/s0132347423010028.

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A class of consistent difference schemes for incompressible Navier–Stokes equations in physical variables and their differential approximations are considered using an algorithm for Gröbner basis construction. Results of investigating the first differential approximations of these schemes, which are obtained by using the authors' programs implemented in the SymPy computer algebra system, are presented. For the difference schemes under consideration, the quadratic dependence of the error for large Reynolds numbers and the inversely proportional dependence for creeping currents are analyzed.

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Levitsky, N. « Improvement of accounting representation of non-current assets ». Galic'kij ekonomičnij visnik 68, n^o 1 (2021) : 37–43. http://dx.doi.org/10.33108/galicianvisnyk_tntu2021.01.037.

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The essence of non-current assets is investigated and their main components are revealed in this paper. The problems of accounting for non-current non-monetary assets, which currently occupy an important share in the total value of assets, are studied. The place of new types of property – computer programs, electronic databases, websites (online stores, electronic printed publications and other electronic media) in the structure of non-current assets in particular, and property of the enterprise in general is determined. It is proved that such property is be closely related to the application of computer equipment and computer networks such as the Internet. In order to summarize the selected features and characteristics of this type of property, it is proposed to combine them into the separate group called «Electronic Property». Allocated objects are neither things nor property rights, the amount of money invested in this property is huge, and the turnover from the sale of goods and services via the Internet (online stores) is significant. On the global scale, such manipulations make it possible to clarify the concept and meaning of the term «intangible assets». The concept of «electronic property» is defined as property that has no material, natural form, which functions exclusively in conjunction with the physical resources of personal computers or computer networks. In order to organize the accounting of the investigated type of property, it is proposed to combine it into a separate accounting group «electronic assets» and to use for reflection in the accounting system the following accounts of the Chart of Accounts: 128 sub-account – «electronic assets», 136 subaccount – «depreciation of electronic assets». The main stages of accounting for non-current assets: identification and definition of non-current assets; classification of non-current assets; evaluation of non-current assets for accounting purposes; criteria, norms, methods of depreciation; principles of objects depreciation impossibility; procedure (methodology) for accounting of non-current assets aiming to determine the financial result are identified.

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Zmejev, D. N., et N. N. Levchenko. « Aspects of Creating Parallel Programs in Dataflow Programming Paradigm ». Informacionnye Tehnologii 28, n^o 11 (17 novembre 2022) : 597–606. http://dx.doi.org/10.17587/it.28.597-606.

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The imperative programming paradigm is the main one for creating sequential and parallel programs for the vast majority of modern computers, including supercomputers. A feature of the imperative paradigm is the sequence of commands. This feature is an obstacle to the creation of efficient parallel programs, since parallelism is achieved at the expense of additional code. One of the solutions to the problem of overhead for parallel computing is the creation of such a computing model and the architecture of the system that implements it, for which the parallel execution of the algorithm is an immanent property. This model is a dataflow computing model with a dynamically formed context and the architecture of the parallel dataflow computing system "Buran". A complete transition to dataflow systems is hampered, among other things, by the conceptual difference between the dataflow programming paradigm and the imperative one. The article compares these two paradigms. First, parallel data processing is an inherent property of a dataflow program. Second, the dataflow program consists of three elements: a set of initial data, a program code, and a parameterizable distribution function. And third, a conceptually different approach to the algorithmization of the task — the data themselves store information about who should process them (in traditional programs, on the contrary, the command stores information about what data should be processed). The article also presents the structure of a dataflow program and the route for creating a dataflow algorithm. The translation of basic algorithmic constructions (following, branching, loops) is considered on the example of simple problems.

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Wilson, J. F., et U. Mahajan. « The Mechanics and Positioning of Highly Flexible Manipulator Limbs ». Journal of Mechanisms, Transmissions, and Automation in Design 111, n^o 2 (1 juin 1989) : 232–37. http://dx.doi.org/10.1115/1.3258988.

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This paper deals with the analysis of lightweight, flexible robotic limbs. A typical limb is a series of polymeric tube elements. One end is fixed and the payload at the other end is manipulated by varying the internal pressure in each element. The theoretical derivations relating limb position and its payload incorporate the nonlinear elastic properties of the element material and large deflections. A computer program stores information about limb position and after each successive limb manipulation the program adaptively upgrades itself to improve positioning accuracy. Results are illustrated with a numerical example.

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Zhang, Yuan. « Study on the Construction of Linguistics Examination Database Based on Computer Network Technology ». Advanced Materials Research 989-994 (juillet 2014) : 5486–90. http://dx.doi.org/10.4028/www.scientific.net/amr.989-994.5486.

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In this paper we use the VB software to programming the group program of tests, combined with neural network residual training principle, establish optimization design model of network examination database. We improve the English linguistics question bank based on computer network technology by using the program and the model, and set up the feedback system of students’ suggestion and Corporate Data Stores system of examination paper, and establish optimization model of network examination database. In order to verify effectiveness and reliability of network test optimization system, we optimize the network examination database of English Linguistics for three times, obtain the optimal distortion curve of test, and analyze optimized test scale. It provides technical support for the research of network English teaching.

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Khorin, A. N. « A Family of Exact Solutions of the Navier-Stokes Equations for the Verification of Computer Programs ». Proceedings of Moscow Institute of Physics and Technology 12, n^o 4 (2020) : 80–89. http://dx.doi.org/10.53815/20726759_2020_12_4_80.

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Serik, M., G. F. Nurbekova et B. B. Akhmetova. « ABOUT SOFTWARE ENVIRONMENTS USING BIG DATA IN THE LEARNING PROCESS ». Bulletin of Kazakh National Women's Teacher Training University, n^o 1 (9 avril 2021) : 76–83. http://dx.doi.org/10.52512/2306-5079-2021-85-1-76-83.

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The article discusses several types of programs for teaching big data and analyzes data on the implementation of big data in some educational institutions. For the introduction and implementation of special courses in the educational process in the areas of magistracy in the educational program Computer Science, the curriculum, educational and methodological complex, digital educational resources are considered. As well as hardware and software that collects, stores, sorts big data, and the introduction into the educational process of theoretical foundations and methods of using the developed technical and technological equipment. This article reflects information on the conduct of a special course on the use of big data in the educational, educational process of senior students and undergraduates of the specialty "Informatics", the Faculty of Information Technologies, LN Gumilyov Eurasian National University. The first module of the course examines the ERA 500 network controller as an example of a turnstile network controller.

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KHETAGUROV, Valery, Evgeny KAMENETSKY, Mikhail GEGELASHVILI et Azamat MARZOEV. « EQUIPMENT MODIFICATION FOR FINE GRINDING OF MINERAL RAW MATERIALS ». Sustainable Development of Mountain Territories 13, n^o 2 (30 juin 2021) : 292–303. http://dx.doi.org/10.21177/1998-4502-2021-13-2-292-303.

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Introduction. The huge energy costs of fine and ultrafine grinding operations have led to numerous studies aimed at developing new devices and methods for producing powdered materials. The first way leads to an increase in specific productivity while maintaining energy consumption at approximately the same level. The second way allows not only to increase the specific productivity, but also to reduce the specific energy consumption, since with a decrease in the exposure time, the body is more easily deformed and destroyed. The grinders in which the intensification of the destruction process is carried out in the first way can include planetary and vibrating mills. The second method of intensification is used in jet and various types of centrifugal mills. It is determined that vertical centrifugal mills are the equipment of a new type that can effectively perform grinding operations at high technological indicators and low energy consumption. The purpose of the research. Development of measures for obtaining a finely dispersed product by destroying mineral raw materials in vertical centrifugal mills by mechanical means. Research methodology. The paper uses a comprehensive research method: analysis of the state of grinding equipment according to literary and patent sources; development of mathematical models of the movement of bulk material in the working space of a vertical centrifugal mill based on the Navie-Stokes equations; computer modeling of the movement of the crushed material using the OpenFOAM package for solving hydrodynamic equations; a solver program was created to perform calculations, implementing the SIMPLER algorithm and using the MRF model; laboratory experiments; granulometric method for the analysis of grinding products; fractional analysis of crushed material with a grain size of 0.08 mm using an X-ray analytical centrifuge ВrооkhаvеnBI-ХDС. The development of measures for the effective evacuation of the crushed product from the working space of a centrifugal mill was evaluated by comparative tests of mills using various design solutions. Research results and discussion 1. It is established that vertical centrifugal mills are the devices of a new type capable of effectively performing grinding operations at high technological indicators and low energy consumption. 2. A mathematical model of the movement of bulk material in the working space of a vertical centrifugal mill has been developed based on the Navier-Stokes equations, which allows determining the speed and direction of movement of material layers at any point in the working space, the energy costs for their movement, the influence of the height of the material column on the nature of its movement in the space above the rotor. 3. The directions of increasing the efficiency of grinding mineral raw materials in a vertical centrifugal mill are determined by reducing the number of radial ribs installed in the cavity of the mill rotor; making cutouts in the radial ribs of the rotor, in the area near the rotor hub; installing coaxial rings in the working space of the mill above the rotor. 4. A method of effective evacuation of the crushed product from the mill body by installing additional screening surfaces in the peripheral part of the working space of the mill has been developed. 5. For the first time, the distribution of the granulometric composition of fine and medium - dispersed crushed product obtained as a result of processing lump dolomite in a centrifugal mill was obtained. It was found that particles with a size class of -0.08 + 0.03 mm are absent in the output of the crushed product from the mill. Conclusions. A mass-produced vertical centrifugal mill will find its effective application at enterprises of the Russian Federation for the preparation of powdered materials and will allow to obtain a significant effect by reducing the price of the final product, simplicity of design and maintenance of equipment, as well as small occupied production areas.

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Kovács, Balázs, I. Czinkota, L. Tolner et Gy Czinkota. « FIT Method for Calculating Soil Particle Size Distribution from Particle Density and Settling Time Data ». Agrokémia és Talajtan 55, n^o 1 (1 mars 2006) : 295–304. http://dx.doi.org/10.1556/agrokem.55.2006.1.32.

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Particle size distribution (PSD) is one of the most important fundamental physical properties of soils, as it determines their physical, chemical, mechanical, geotechnical, moreover environmental behaviour. Although the measurement of PSD with different techniques is commonly performed in soil laboratories, their automation and continuous PSD curve generation have not been solved yet. However, there are some physical principles, various sensors and different data storing methods for measuring the density-time function. In the present paper a possible solution is introduced for the measurement of the soil particle density database as a function of settling time. The equipment used for this purpose is an areometer that is widely used e.g. for determining the sugar content of must, or the alcohol content of distilled spirits, etc. The device is equipped with patent pending capacitive sensors on the neck of the areometer. It measures the changes in the water levels nearby the neck of the areometer in 1 μm units with <10 μm accuracy. The typical water level changes are 3-5 cm, which makes possible a very accurate determination of particle density changes due to settling in particle size analysis. The measured signals are stored in the equipment's memory and can be downloaded to the controller computer via a modified USB port. Data evaluation can be carried out online or later. The large number of measured data points led to the introduction of a new evaluation method, the Method of FInite Tangents or shortly the “FIT Method”. The dispersed soil particle system is considered as the aggregation of many mono-disperse systems. From this it follows that the measured density-time function can be divided into grain size fractions with tangent lines drawn to finite, but optional points. These tangent lines are suitable for calculating the settling speed of a given fraction, as the changing speed of density is equal to the multiplication of settling speed and mass of the given grain size fraction. The settling speed of all fractions is calculable by using the Stokes law, so the mass of all of the floating fraction can be calculated. Because the soil suspension is a poly-disperse system, the measured density decrease can be considered as an integration of finite mono-disperse systems. From this, it follows that it can be interpreted as the sum of linear density vs. time functions. If the mass of each grain size fraction is known, the particle size distribution is calculable. The method is relatively easily programmed and the intervals of grain size fractions are freely adjustable, so with this program almost all types of particle size distribution are calculable, not only those being uniform. Using the appropriate controller and evaluation program, soil particle size distribution can be calculated immediately after downloading the measured data. This technique does not need more sample preparation than past methods. The automated reading lessens the manpower required for performing the measurement - which also reduces human error sources - and provides very detailed PSD data that has advantages, among others, like revealing multi-modality in the particle-size distribution.

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Betelin, V. B., A. G. Kushnirenko, A. G. Leonov et K. A. Mashchenko. « Basic Programming Concepts as Explained for Preschoolers ». International Journal of Education and Information Technologies 15 (9 septembre 2021) : 245–55. http://dx.doi.org/10.46300/9109.2021.15.25.

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The development of information technologies has formed a socio-economic request to reduce the age at which children can be introduced to programming. After 6 years’ efforts, the authors managed to develop and on a large scale introduce a one-year programming course for preschoolers, which is built on a metaphor of programmed control. During the course development, a set of basic programming concepts was selected and specified to be mastered by preschoolers aged 6+ in the activity-game form. This set of concepts goes back to Seymour Papert's ideas about teaching programming by writing programs that control moving objects using intuitive sets of commands. The main feature of the proposed system of concepts, allow at the initial stage of training to demonstrate and assimilate all the elements of the concept in the real, not in the virtual world. In the picture of the World, which we explain and demonstrate to children, only one function remains at the computer - the execution of the program it has memorized. Everything else happens in the real world. In the real world, an environment is created in which a real robot will move. In the real world, a program is created from tangible objects, which will then be "shown" to the computer so that it stores it in its memory and can then execute it at the command of a human. In the real world, obeying the signals of the computer, the robot performs the work stipulated by the program. This allows you to begin acquaintance with the programming of children from 4 years old, without working individually or collectively with electronic screens, which in today's Russia is prohibited by federal medical authorities in the educational process of children under 5 years old. The course is built on the text-free pictographic programming system PiktoMir developed by Russian Academy of Sciences. The methodological content of the course allows each preschooler to gain experience in the development and debugging of 120-150 simple programs by the end of the course. The final part of the article discusses the authors' plans for the development of a three-year textless programming course, methodologically and instrumentally connected with the primary school programming course.

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