Academic literature on the topic 'Uniform accelerated movement of a boundary'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Uniform accelerated movement of a boundary.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Uniform accelerated movement of a boundary"
1
Van Leeuwen, Johan L. "Why the chameleon has spiral–shaped muscle fibres in its tongue." Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 352, no. 1353 (May 29, 1997): 573–89. http://dx.doi.org/10.1098/rstb.1997.0039.
Full textAbstract:
The intralingual accelerator muscle is the primary actuator for the remarkable ballistic tongue projection of the chameleon. At rest, this muscle envelopes the elongated entoglossal process, a cylindrically shaped bone with a tapering distal end. During tongue projection, the accelerator muscle elongates and slides forward along the entoglossal process until the entire muscle extends beyond the distal end of the process. The accelerator muscle fibres are arranged in transverse planes (small deviations are possible), and form (hitherto unexplained) spiral–shaped arcs from the peripheral to the internal boundary. To initiate tongue projection, the muscle fibres probably generate a high intramuscular pressure. The resulting negative pressure gradient (from base to tip) causes the muscle to elongate and to accelerate forward. Effective forward sliding is made possible by a lubricant and a relatively low normal stress exerted on the proximal cylindrical part of the entoglossal process. A relatively high normal stress is, however, probably required for an effective acceleration of muscle tissue over the tapered end of the process. For optimal performance, the fast extension movement should occur without significant (energy absorbing) torsional motion of the tongue. In addition, the tongue extension movement is aided by a close packing of the muscles fibres (required for a high power density) and a uniform strain and work output in every cross–section of the muscle. A quantitative model of the accelerator muscle was developed that predicts internal muscle fibre arrangements based on the functional requirements above and the physical principle of mechanical stability. The curved shapes and orientations of the muscle fibres typically found in the accelerator muscle were accurately predicted by the model. Furthermore, the model predicts that the reduction of the entoglossal radius towards the tip (and thus the internal radius of the muscle) tends to increase the normal stress on the entoglossal bone.
2
Campos, Lucas Silveira, Éder Lima de Albuquerque, and Luiz Carlos Wrobel. "An ACA accelerated isogeometric boundary element analysis of potential problems with non-uniform boundary conditions." Engineering Analysis with Boundary Elements 80 (July 2017): 108–15. http://dx.doi.org/10.1016/j.enganabound.2017.04.004.
Full text
3
Boag, Amir, Uri Shemer, and Raphael Kastner. "Non-uniform grid accelerated local–global boundary condition (NG-LGBC) for acoustic scattering." Computer Methods in Applied Mechanics and Engineering 195, no. 29-32 (June 2006): 3608–21. http://dx.doi.org/10.1016/j.cma.2005.02.028.
Full text
4
Котов and P. Kotov. "CONSTRUCTIVE ASPECTS OF ELECTRODYNAMIC." Modeling of systems and processes 9, no. 1 (September 23, 2016): 8–10. http://dx.doi.org/10.12737/21617.
Full textAbstract:
Dynamic models of the accelerated shift of the elementary particle with a charge in the electromagnetic field of measurable intensity are considered and the substantial relations, the distinctive state and solutions of problems in connection with the equations of stable elementary particle movement in a uniform magnetic field of the fixed intensity are offered.
5
Lian, Xugang, Zoujun Li, Hongyan Yuan, Haifeng Hu, Yinfei Cai, and Xiaoyu Liu. "Determination of the Stability of High-Steep Slopes by Global Navigation Satellite System (GNSS) Real-Time Monitoring in Long Wall Mining." Applied Sciences 10, no. 6 (March 12, 2020): 1952. http://dx.doi.org/10.3390/app10061952.
Full textAbstract:
Surface movement and deformation induced by underground coal mining causes slopes to collapse. Global Navigation Satellite System (GNSS) real-time monitoring can provide early warnings and prevent disasters. A stability analysis of high-steep slopes was conducted in a long wall mine in China, and a GNSS real-time monitoring system was established. The moving velocity and displacement at the monitoring points were an integrated response to the influencing factors of mining, topography, and rainfall. Underground mining provided a continuous external driving force for slope movement, the steep terrain provided sufficient slip conditions in the slope direction, and rainfall had an acceleration effect on slope movement. The non-uniform deformation, displacement field, and time series images of the slope body revealed that ground failure was concentrated in the area of non-uniform deformation. The non-uniform deformation was concentrated ahead of the working face, the speed of deformation behind the working face was reduced, the instability of the slope body was increased, and the movement of the top of the slope was larger than at the foot. The high-steep slope stability in the mine was influenced by the starting deformation (low stability), iso-accelerated deformation (increased stability), deformation deceleration (reduced stability), and deformation remaining unchanged (improved stability).
6
Meng, Jun-Nan, Guang Pan, and Yong-Hui Cao. "Element-Free Galerkin method for dynamic boundary flow problems." Modern Physics Letters B 34, no. 24 (July 1, 2020): 2050257. http://dx.doi.org/10.1142/s0217984920502577.
Full textAbstract:
This paper focuses on the study of dynamic boundary flow problems based on the Element-Free Galerkin method. First, Navier–Stokes equation is discretized with the Galerkin method. The inertial term in the equation is discretized with the method of the speed term and direct deduction, respectively. The penalty function method is used to deal with the pressure and the essential boundary condition in the equation, and the discretization of two-dimensional N–S equation based on the EFG method is established. However, irregular changes in boundary conditions are often encountered in practical fluid problems. For example, the motion of flapping-foil is not uniform relative to the flow. In this paper, numerical experiments are carried out for the flow problems with non-uniform boundary motions. The problem which a plate with non-uniform drag movement above a rectangular tank filled with water is studied with the EFG method. The feasibility of the proposed algorithm is verified by comparison with the FEM method. Then, the procession of the water in the tank is stimulated. In the end, the influence of different calculation time steps on the accuracy of the solution is discussed.
7
Ehrenstein, Uwe, Matthieu Marquillie, and Christophe Eloy. "Skin friction on a flapping plate in uniform flow." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 372, no. 2020 (July 28, 2014): 20130345. http://dx.doi.org/10.1098/rsta.2013.0345.
Full textAbstract:
To calculate the energy costs of swimming or flying, it is crucial to evaluate the drag force originating from skin friction. This topic seems not to have received a definite answer, given the difficulty in measuring accurately the friction drag along objects in movement. The incoming flow along a flat plate in a flapping normal motion has been considered, as limit case of a yawed cylinder in uniform flow, and applying the laminar boundary layer assumption it is demonstrated that the longitudinal drag scales as the square root of the normal velocity component. This lends credit to the assumption that a swimming-like motion may induce a drag increase because of the compression of the boundary layer, which is known as the ‘Bone–Lighthill boundary-layer thinning hypothesis’. The boundary-layer model however cannot predict the genuine three-dimensional flow dynamics and in particular the friction at the leeward side of the plate. A multi-domain, parallel, compact finite-differences Navier–Stokes solution procedure is considered, capable of solving the full problem. The time-dependent flow dynamics is analysed and the general trends predicted by the simplified model are confirmed, with however differences in the magnitude of the friction coefficient. A tentative skin friction formula is proposed for flow states along a plate moving at steady as well as periodic normal velocities.
8
Du, Jin Song, and Xin Bi. "An Adaptive Interacting Multiple Model for Vehicle Target Tracking Method." Advanced Materials Research 718-720 (July 2013): 1286–89. http://dx.doi.org/10.4028/www.scientific.net/amr.718-720.1286.
Full textAbstract:
In the field of traffic safety vehicle target tracking prediction as the background, this paper proposes an adaptive interacting multiple model tracking algorithm. According to the field of transportation vehicle movement state characteristics, based on the uniform (CV) and uniformly accelerated motion (CA) model, based on new information structure model of motion of the likelihood function, online adaptive adjustment model of the noise variance and the Markov matrix, realization of maneuvering target movement model and model set adaptation, not only improved IMM algorithm for tracking accuracy, and enhances the real-time performance of system, the simulation results show that, the algorithm for tracking precision compared to the traditional IMM method has bigger improvement.
9
Zhou, Wenting. "Is the Fulling–Davies–Unruh effect valid for the case of an atom coupled to quantum electromagnetic field?" Modern Physics Letters A 31, no. 34 (October 21, 2016): 1650189. http://dx.doi.org/10.1142/s0217732316501893.
Full textAbstract:
We study, from the viewpoint of a co-accelerated observer, the average rate of change of atomic energy for an atom in uniform acceleration and coupled to quantum electromagnetic field at a thermal state with an arbitrary temperature T. We show that only when the temperature of the thermal state in the co-accelerated frame is assumed to be the Fulling–Davies–Unruh (FDU) temperature, T = a/2[Formula: see text], can the average rate of change of atomic energy in a local inertial frame be recovered, which exemplifies the equivalence between the Minkowski vacuum and a thermal bath of Rindler particles. This conclusion is verified to be valid not only in a free spacetime, but also in a spacetime with a boundary.
10
Beldi, M., and A. Maghrebi. "Some New Results for the Study of Acoustic Radiation within a Uniform Subsonic Flow Using Boundary Integral Method." Advanced Materials Research 488-489 (March 2012): 383–95. http://dx.doi.org/10.4028/www.scientific.net/amr.488-489.383.
Full textAbstract:
In this paper, a reformulation of the Helmholtz integral equation for tridimesional acoustic radiation in a uniform subsonic flow is presented. An extension of the Sommerfeld radiation condition, for a free space in a uniform movement, makes possible the determination of the convected Green function, the elementary solution of the convected Helmholtz equation. The gradients of this convected Green function are, so, analyzed. Using these results, an integral representation for the acoustic pressure is established. This representation has the advantage of expressing itself in terms of new surface operators, which simplify the numerical study. For the case of a regular surface, the evaluation of the free term associated with the singular integrals shows that it is independent of the Mach number of the uniform flow. A physical interpretation of this result is offered. A numerical approximation method of the integral representation is developed. Furthermore, for a given mesh, an acoustic discretization criterion in a uniform flow is proposed. Finally, numerical examples are provided in order to validate the integral formula.
Dissertations / Theses on the topic "Uniform accelerated movement of a boundary"
1
Gnatenko, A. S., O. V. Zhyla, and A. G. Nerukh. "Airy Pulse Transformation by an Accelerated Medium Boundary." Thesis, CAOL, 2019. http://openarchive.nure.ua/handle/document/15101.
Full textAbstract:
In the statement of a problem with a moving boundary there is one more idealization, namely, movement stationarity assuming that the movement has begun at infinite past time. Abandoning this idealization, by considering a movement that begins at a finite moment of time, leads to the appearance of new peculiarities in the wave transformation on a moving boundary. In this paper such peculiarities are considered with an abrupt uniform movement of a boundary beginning at zero moment of time, as well as with a smooth "turning on" of a boundary movement according to a relativistic uniformly accelerated law. In the latter approach the continuity of a boundary velocity change allows the development of the evolution of the wave transformation process to be traced.
Conference papers on the topic "Uniform accelerated movement of a boundary"
1
Simens, Mark P., and Ayse G. Gungor. "The Effect of Surface Roughness on Laminar Separated Boundary Layers." In ASME Turbo Expo 2013: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/gt2013-95810.
Full textAbstract:
Roughness effects on a laminar separation bubble, formed on a flat plate boundary layer due to a strong adverse pressure gradient similar to those encountered on the suction side of typical low-pressure turbine blades, are studied by direct numerical simulation. The discrete roughness elements that have a uniform height in the spanwise direction and ones that have a height that is a function of the spanwise coordinate are modeled using the immersed boundary method. The location and the size of the roughness element are varied to study the effects on boundary development and turbulent transition, and it was found that the size of the separation bubble can be controlled by positioning the roughness element away from the separation bubble. Roughnesses that have a height that varies in a periodic manner in the spanwise direction have a big influence on the separation bubble. The separation point is moved downstream due to the accelerated flow in the openings in the roughness element, which also prevents the formation of the recirculation region after the roughness element. The reattachment point is moved upstream, while the height of the separation bubble is reduced. These numerical experiments indicate that laminar separation and turbulent transition, are mainly affected by the type, the height, and the location of the roughness element. Finally a comparison between the individual influence of wakes and roughness on the separation is made. It is found that the transition of the separated boundary layer with wakes occurs at almost the same streamwise location as that induced by the three-dimensional roughness element.
2
Adachi, Masaki, Fujio Inasaka, Koki Shiozaki, and Izuo Aya. "Research on Waterhammer Caused by a Rapid Gas Production in an LWR Severe Accident: 2 — 2D Analysis With RELAP5-3D." In ASME/JSME 2003 4th Joint Fluids Summer Engineering Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/fedsm2003-45273.
Full textAbstract:
Water hammer load induced by ex-vessel steam explosion, which is resulted from molten fuel in water pool, still includes many uncertain factors in safety research against severe accident for design criteria of next generation nuclear power plant. One of the factors is degree of coherency in water bulk accelerated by the explosion. If high-coherent movement in many pieces of water bulk in the pool (as many pieces of the bulk move with coincidence and same direction), an excessive load will be applied to inner structure of the plant. To evaluate the factor, 2 dimensional analysis to simulate the coherent movement induced by pressurized air injection in containment vessel, has been examined with RELAP5-3D, which is one of the most popular codes in nuclear engineering. This 2D analysis simulated glowing single component zone of pressurized air, regarded as large bubble, and cloud-like interface around the zone observed in the experiment where momentum is transferred from the air to the water. This analysis also predicted virtually uniform acceleration of the bulk and detailed 2D flow proceeded to air penetration through the water. And water hammer pressure could also be simulated, with evaluating sonic speed drop through two-component mixed layer around the bulk.
3
Bhayadia, Amit, Anthony Olivett, Tarunraj Singh, and M. Amin Karami. "Generation of Travelling Waves Using Tracking Control Method." In ASME 2021 Conference on Smart Materials, Adaptive Structures and Intelligent Systems. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/smasis2021-67559.
Full textAbstract:
Abstract Travelling wave patterns observed in the movement of certain aquatic animals has motivated research in the modification of flow behavior, especially to deal with boundary layer separation in airplane plane wings. Research has shown that inducing travelling waves on the top surface of the wing can generate sufficient momentum to prevent boundary layer separation without increasing the drag. Due to this interesting property, generation of travelling waves on solid surfaces is being widely studied. Recently methods such as two-mode excitation, active sink and impedance matching have shown promise in generation of uniform travelling waves in solids with the help of piezo electric actuators. Unfortunately, there are some challenges involved in the experimental application of these methods. These open loop methods require exact knowledge of the system dynamics therefore, uncertainties in the system dynamics can affect the uniformity and the amplitude of the travelling waves. Some methods rely on selective mode excitation, which can cause interference from unwanted modes if the transient behavior of the system is not accounted. A tracking control method is proposed that augments the open-loop piezo actuation method (two-mode excitation) and provides a more robust method for generating uniform travelling waves. The periodic signal tracking control method drives the output of the temporal part of the distributed parameter system to a desirable output. In addition, the controller alters the reference signal such that the parasitic behavior of unnecessary modes is cancelled out. The combination of the mode suppression and signal tracking deals with the challenges of the piezo actuation methods and add to its performance by improving the quality of the generated wave.
4
Rozzi, Jay C., Frank P. Incropera, and Yung C. Shin. "Transient, Three-Dimensional Heat Transfer Model for the Laser Assisted Machining of Ceramic Materials." In ASME 1997 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1997. http://dx.doi.org/10.1115/imece1997-0833.
Full textAbstract:
Abstract A three-dimensional, unsteady heat transfer model has been formulated for predicting the temperature field associated with the laser assisted machining (LAM) of ceramic materials. The model considers a rotating silicon nitride workpiece heated by a translating CO2 laser, with material removal occurring at a location corresponding to the cutting tool. Movement of the workpiece relative to the laser source and cutting tool at the conclusion of a preheat phase significantly influences the workpiece temperature distribution, particularly at the material removal plane, by facilitating the transport of thermal energy deposited by the laser to the chamfer (the boundary between removed and unremoved material). Relative to predictions without material removal, the chamfer represents a significant thermal resistance to heat transfer, thereby increasing temperatures in the material removal plane at the conclusion of the preheat phase and causing a slower decay in the average temperature in this region as machining continues. The temperature distribution within the machined material remains nearly uniform for the investigated operating condition.
5
Iorio, C. S., and O. A. Kabov. "Heat Transfer Enhancement in Evaporating Mini-Layers: Effects of an Inert Gas Flow." In ASME 2007 5th International Conference on Nanochannels, Microchannels, and Minichannels. ASMEDC, 2007. http://dx.doi.org/10.1115/icnmm2007-30172.
Full textAbstract:
When a layer of volatile liquid is subject to a flow of inert gas, a non-uniform distribution of the evaporation rate is generated all along the interface. Being evaporation stronger at the inlet boundary of the layer, because of the maximal efficiency of the inert gas flow in removing vapor from the interface, a thermal gradient along the interface is generated. Two opposite mechanisms regulate the movement of the interface: the shear stress of the gas that entrains the interface in the direction of the flow and the thermo-capillary stress that forces the interface to move against the flow direction. Moreover, because of the overall cooling of the interface due to the evaporative process, a gradient normal to the interface is also created. It results in a potentially unstable situation that is strongly influenced by the flow rate of inert gas, the layer thickness and the liquid thermo-physical properties. The goal of the present work is to study numerically if and how the dynamic evolution of the liquid layer is driven by the above-mentioned mechanisms. The main results concern the evaluation of the influence of the thermal instability patterns, eventually generated by the concurrent action of non-uniform evaporation and thermo-capillary motion, on the heat transfer at the bottom liquid. The distribution of temperature and velocity in the gas and liquid bulk phase for different mass flow rate of inert gas has also been of interest.
6
Onokoko, Charles Landa, and Nicolas Galanis. "Stratification in Isothermal Ice-Slurry Pipe Flow." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-63801.
Full textAbstract:
A single-phase 3D model for isothermal laminar and turbulent flow of an ice slurry in a horizontal pipe is used to investigate the effects of the uniform inlet velocity and ice concentration on their axial evolution. The slurry is modeled as a Newtonian fluid with effective local properties depending on the local ice concentration. Despite the relative simplicity of this model (compared to the two-phase models used elsewhere) its numerical solution gives results which correctly reflect experimental observations. Specifically, these results show that as the fluid moves downstream the ice concentration increases in the upper part of the pipe and it decreases in the lower part. The velocity profile is principally influenced by the boundary layer growth close to the inlet but further downstream it becomes asymmetrical with respect to the horizontal symmetry plane with higher velocities in the lower part of the pipe. The differences between the values in the upper and lower parts of the pipe are much more important in the case of laminar flow. The results are analyzed by considering the phenomena influencing the ice particle movement (buoyancy and diffusion) and the relation between ice concentration and the thermophysical properties of the slurry.
7
Ge, Liang, Mingtian Xu, and Lin Cheng. "The Application of Entransy Dissipation Theory in the Volume-to-Point Heat Conduction Problem." In 2010 14th International Heat Transfer Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/ihtc14-22271.
Full textAbstract:
Recent advances in semiconductor technologies are accompanied by an accelerated increase in power density level from high performance chips such as microprocessors. The thermal management of electronic devices, especially meeting the limitations on maximum operating temperature and ensuring temperature uniformity across the chip, becomes one of the most critical issues in the electronic industry. Much effort is devoted to devising the efficient electronic cooling technologies. One cooling strategy proposed by Bejan is that the heat generated in a finite volume may be removed to a point on the boundary through some embedded conducting paths with high conductivity in the substrate. The problem is to optimize the allocation of the conducting paths so that the generated heat can be most effectively dissipated and the highest temperature in the domain is minimized, which is called the volume-to-point conduction problem. Bejan developed the constructal method to optimize the high conductivity material allocation. However the uniformly distributed heat source is always assumed in Bejan’s discuss, which is not consistent with the reality in the chips or other integrated circuits. In the present work, the volume-to-point conduction problem with non-uniform heat sources is formulated in the framework of the entransy dissipation theory and is solved by the variational method and finite element method. The tree-shape distribution of the conducting paths is obtained, which agrees with the constructal theory.
8
Cayeux, Eric. "Modelling of the Movement of a Prolate Particle in the Steady State Flow of a Non-Newtonian Fluid in an Inclined Annulus With Inner String Rotation." In ASME 2019 38th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/omae2019-95049.
Full textAbstract:
Abstract The determination of the slip velocity, or whether a solid particle will sediment, during its transport is of prime importance for hole cleaning evaluations during drilling operations. Yet, this task is complexified by the asymmetry of the annulus when the central pipe axis does not coincide with the borehole central line and when the inner string rotates, especially since drilling fluids typically follow a yield stress power law rheological behavior. This paper describes the modelling of the movement of a particle in such conditions yet with the following simplifications: the inner tube is eccentric but has a uniform movement, the shape of the particle is assimilated to a prolate, the change of shear rates in the fluid around the slipping particle is neglected and collisions between particles are not considered. Otherwise, gravitational effects are incorporated by accounting for the mass density difference between the particle and the surrounding fluid mixture and by considering the borehole inclination. The particle spin is also estimated as it plays an important role in the determination of the drag and lift forces. The solution to the differential equations that describe the time evolution of the position and orientation of the particle, depend largely upon the initial conditions. Therefore, an ensemble of boundary conditions is generated at a starting cross-section along the annulus and the resulting particle trajectories are estimated. It is then possible to estimate a probabilistic slip velocity for particles of the considered dimensions, far away from the entrance region. This probabilistic approach allows to define a critical transport fluid velocity as the lower limit of the bulk fluid velocity by which no particle risk to settle. Similarly, one can define a critical settling fluid velocity as the upper limit of the bulk fluid velocity where every particle will sediment regardless of the initial conditions. With the described modelling of the particle movement and its associated statistical methods, it is possible to quantitatively estimate the spatial distribution of particles in any cross-section. For those particles that get trapped between the tool-joint and the borehole, it is then possible to estimate their size reduction by grinding, resulting from the rotation of the tool-joint on the borehole wall. The grinding process impacts the particle size distribution passed a tool-joint. By applying this method iteratively up to the annulus outlet, it is possible to estimate the particle size distribution of the drill-cuttings when they arrive at the shale-shakers.
9
Shimamura, Junji, Kyono Yasuda, Nobuyuki Ishikawa, and Shigeru Endo. "Ductile Fracture Behavior of Bainite-MA Dual Phase Steels." In 2014 10th International Pipeline Conference. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/ipc2014-33484.
Full textAbstract:
In order to achieve safety and reliability of the pipeline installed in seismic region, it is quite important to apply the high-strength linepipes with sufficient strain capacity against buckling and weld fracture by the seismic ground movement. Dual-phase microstructure control is an essential measure for improving strain capacity of linepipe steels. Ferrite-bainite or bainite-MA microstructures are practically applied to the linepipes for the strain-based design to achieve higher deformability which has low Y/T (Yield/Tensile strength) ratio and high uniform elongation even after pipe coating. On the other hand, dual-phase steels tend to show lower Charpy energy in the upper shelf region than single-phase steel. It is considered that void nucleation and growth is enhanced in the dual-phase steels due to the strain concentration at the boundary between two different phases, resulting in early cracking in the specimen that leads to lower Charpy energy. The Charpy energy of the bainite-MA dual-phase steels was strongly affected by the volume fraction and size of MA. In the case of Bainite-MA steels with fewer volume fraction of MA and smaller size of MA, the sample showed higher Charpy energy. Ductile fracture behavior was investigated through several kinds of Charpy impact tests in order to clarify the effect of these microstructure differences on the Charpy energy in the upper shelf region. From the SEM observation, it was found that void nucleation was enhanced in the sample with higher volume fraction of MA and larger size of MA. It is considered that the increase of boundary area that works as void nucleation site affected these results. Experimental results were mainly discussed in this paper.
10
Jaladi, Divya, Matthew Pearce, C. W. Van Neste, and Ethan Languri. "Near Field Resonant Capacitive Heating of Water." In ASME 2021 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/imece2021-72073.
Full textAbstract:
Abstract Remediation of water from tailings is a critical and challenging issue in many industries, particularly in oil sand refineries and waste water treatment. Mining of the Canadian oil sands, also one of the largest known crude petroleum reserve in the world, is done to extract bitumen by the processes like hot water extraction, resulting in numerous amounts of tailings (large ponds). Techniques that can achieve contaminant separation over large surface areas/volumes, with low energy input, and at a low economic investment are of primary interest. Hence, such techniques can be applied for the manufacturing industries with the similar concerns. In this paper, a di-electric heating method is presented that combines electrical standing wave voltage amplification with porous interface (carbon foam) materials to intensify water evaporation. The system targets the di-electric loss tangent of the aqueous solution accompanied with porous interface by operating at a high voltage and frequency in the low megahertz (1–5 MHz). The non-uniform charge distributions across the interface material enables distributed heat localization at the air-water/material boundary, therefore avoiding bulk heating. The most important parameters determining efficiency of capacitive heating are determining the resonant frequency of material in contact with the heating end of helix, and properties of the interface material. Different porous configurations treated for the application were applied as interface layers and the experimental results demonstrate an 80% increase in evaporation rates compared to solar and natural heating. The combination of electrical heating with reduced heat losses results in accelerated vapor generation. Hence, results showcase heat localization at the interface, electric field at the heating boundary and energy requirements for the mentioned scenario. The proposed method offers a promising solution to localize heat over a large area by application of low-cost porous materials and high voltage/high frequency electrical resonators for use in water treatment, remediation, and go further with distillation applications for water reclamation.