Journal articles: 'Cylinder extraction'

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Moradi, Saed, Denis Laurendeau, and Clement Gosselin. "Multiple Cylinder Extraction from Organized Point Clouds." Sensors 21, no. 22 (November 17, 2021): 7630. http://dx.doi.org/10.3390/s21227630.

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Most man-made objects are composed of a few basic geometric primitives (GPs) such as spheres, cylinders, planes, ellipsoids, or cones. Thus, the object recognition problem can be considered as one of geometric primitives extraction. Among the different geometric primitives, cylinders are the most frequently used GPs in real-world scenes. Therefore, cylinder detection and extraction are of great importance in 3D computer vision. Despite the rapid progress of cylinder detection algorithms, there are still two open problems in this area. First, a robust strategy is needed for the initial sample selection component of the cylinder extraction module. Second, detecting multiple cylinders simultaneously has not yet been investigated in depth. In this paper, a robust solution is provided to address these problems. The proposed solution is divided into three sub-modules. The first sub-module is a fast and accurate normal vector estimation algorithm from raw depth images. With the estimation method, a closed-form solution is provided for computing the normal vector at each point. The second sub-module benefits from the maximally stable extremal regions (MSER) feature detector to simultaneously detect cylinders present in the scene. Finally, the detected cylinders are extracted using the proposed cylinder extraction algorithm. Quantitative and qualitative results show that the proposed algorithm outperforms the baseline algorithms in each of the following areas: normal estimation, cylinder detection, and cylinder extraction.

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Junwu, Wu, and Yin Zhongjun. "Numerical Investigation on Vortex-Induced Vibration Energy Extraction Efficiency of Double Circular Cylinders In Tandem Arrangement at Low Reynolds Number." MATEC Web of Conferences 153 (2018): 05001. http://dx.doi.org/10.1051/matecconf/201815305001.

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Vortex shedding from a bluff body results in fluctuating forces acting on the bluff body, which may induce vibration of the bluff body when the bluff body is elastically mounted or deformable. Researchers put forward an idea that we can ex-tract energy from the water flow based on VIV at low flow velocity. Although plenty of researches on parameters of VIV are already presented, however, the improvement of energy extraction efficiency still needs further study. According to the previous research, this essay has simulated flow-induced vibration of tandem double circular cylinders when Reynolds number is 100. Working condition has been considered as the fixed upstream cylinder and the free vibration of the downstream cylinder. The influence of the mass coefficient and the two cylinders spacing ratio on the downstream cylinder’s energy obtained from the fluid is studied. Analysis results show that, the maximum value of the energy extraction efficiency is before the frequency locked range. In the case of large spacing ratio (L/D=7~9), the phenomenon of "beat vibration" appears on the downstream cylinder. The results of this work could provide reference for the improvement of energy extraction efficiency and the design of VIV converter.

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Karim, F., B. Farouk, and I. Namer. "Natural Convection Heat Transfer From a Horizontal Cylinder Between Vertical Confining Adiabatic Walls." Journal of Heat Transfer 108, no. 2 (May 1, 1986): 291–98. http://dx.doi.org/10.1115/1.3246918.

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This paper reports an experimental study of natural convection heat transfer from a horizontal isothermal cylinder between vertical adiabatic walls. Some of the industrial applications of this problem are cooling and casing design of electronic equipment, nuclear reactor safety, and heat extraction from solar thermal storage devices. Heat transfer from 3.81 cm and 2.54 cm diameter cylinders was determined by measuring the electric power supplied to the heater, which was placed inside the cylinders, and correcting for radiation and end losses. Average Nusselt numbers were determined for a Rayleigh number range of 2 × 103 to 3 × 105 and wall spacing to cylinder diameter ratios of 1.5, 2, 3, 4, 6, 8, 10, 12, and ∞. It was found that the confinement of a heated horizontal cylinder by adiabatic walls enhances the heat transfer from the cylinder continuously. This effect is more pronounced at low Rayleigh numbers. A maximum relative enhancement of 45 percent was obtained over the range of experimental conditions studied. Schlieren and flow visualization studies were conducted at selected values of Rayleigh number and wall spacing to cylinder diameter ratios to further explain the heat transfer characteristics and the associated flow physics of the present problem.

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Kasten, Jens, Christoph Petz, Ingrid Hotz, Hans-Christian Hege, Bernd R. Noack, and Gilead Tadmor. "Lagrangian feature extraction of the cylinder wake." Physics of Fluids 22, no. 9 (September 2010): 091108. http://dx.doi.org/10.1063/1.3483220.

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Tilton, Nils, and Denis Martinand. "Taylor–Couette–Poiseuille flow with a weakly permeable inner cylinder: absolute instabilities and selection of global modes." Journal of Fluid Mechanics 849 (June 26, 2018): 741–76. http://dx.doi.org/10.1017/jfm.2018.437.

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Variations in the local stability of the flow in a Taylor–Couette cell can be imposed by adding an axial Poiseuille flow and a radial flow associated with one or both of the cylinders being permeable. At a given rotation rate of the inner cylinder, this results in adjacent regions of the flow that can be simultaneously stable, convectively unstable, and absolutely unstable, making this system fit for studying global modes of instability. To this end, building on the existing stability analysis in absolute modes developing over axially invariant base flows, we consider the case of axially varying base flows in systems for which the outer cylinder is impermeable, and the inner cylinder is a weakly permeable membrane through which the radial flow is governed by Darcy’s law. The frameworks of linear and nonlinear global modes are used to describe the instabilities and assess the results of direct numerical simulations using a dedicated pseudospectral method. Three different axially evolving set-ups are considered. In the first, fluid injection occurs along the full inner cylinder. In the second, fluid extraction occurs along the full inner cylinder. Besides its fundamental interest, this set-up is relevant to filtration devices. In the third, fluid flux through the inner cylinder evolves from extraction to injection as cross-flow reversal occurs. In agreement with the global mode analyses, the numerical simulations develop centrifugal instabilities above the predicted critical rotation rates and downstream of the predicted axial locations. The global mode analyses do not fully explain, however, that the instabilities observed in the numerical simulations take the form of axial stacks of wavepackets characterized by jumps of the temporal frequency.

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Yuxian, Zhang, Yang mengke, Wang Hong, and Liu Binbin. "Design and Finite Element Analysis of Water Jet Energy Accumulator Barrel." MATEC Web of Conferences 153 (2018): 06011. http://dx.doi.org/10.1051/matecconf/201815306011.

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In order to solve the yielding failure problem of water jet energy accumulator barrel due to high pressure, the prestressed composite structure design and the theory of equal strength are used to determine the parameters of accumulator barrel, such as the internal cylinder of the composite cylinder, the radii of the inner and outer cylinders, the radius of sub-layer and the optimal interference. Then the ANSYS software is used to analyze the cylinder model with the finite element method, the equivalent stress of the effective node along the wall thickness of the simulation model is obtained by path extraction method and the distribution curves of the equivalent stress along the wall thickness with different internal pressure are also obtained. By analyzing the simulated results and curves, the design parameters of accumulator barrel meet the expected strength requirement.

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Liu, Yuanpeng. "GEOMETRIC PARAMETERS EXTRACTION OF SPHERE, CYLINDER AND CONE." Chinese Journal of Mechanical Engineering 41, no. 11 (2005): 144. http://dx.doi.org/10.3901/jme.2005.11.144.

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Shibata, Shinpei, and Shota Kisaka. "On the angular momentum extraction from the rotation powered pulsars." Monthly Notices of the Royal Astronomical Society 507, no. 1 (August 2, 2021): 1055–63. http://dx.doi.org/10.1093/mnras/stab2206.

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ABSTRACT The rotation powered pulsar loses angular momentum at a rate of the rotation power divided by the angular velocity Ω*. This means that the length of the lever arm of the angular momentum extracted by the photons, relativistic particles, and wind must be on average c/Ω*, which is known as the light cylinder radius. Therefore, any deposition of the rotation power within the light cylinder causes insufficient loss of angular momentum. In this paper, we investigate two cases of this type of energy release: polar cap acceleration and Ohmic heating in the magnetospheric current inside the star. As for the first case, the outer magnetosphere beyond the light cylinder is found to compensate the insufficient loss of the angular momentum. We argue that the energy flux coming from the sub-rotating magnetic field lines must be larger than the solid-angle average value, and as a result, an enhanced energy flux emanating beyond the light cylinder is observed in different phases in the light curve from those of emission inside the light cylinder. As for the second case, the stellar surface rotates more slowly than the stellar interior. We find that the way the magnetospheric current closes inside the star is linked to how the angular momentum is transferred inside the star. We obtain numerical solutions that shows that the magnetospheric current inside the star spreads over the polar cap magnetic flux embedded in the star in such a way that electromotive force is gained efficiently.

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Nishi, Yoshiki, Yuta Ueno, Masachika Nishio, Luis Antonio Rodrigues Quadrante, and Kentaroh Kokubun. "Power extraction using flow-induced vibration of a circular cylinder placed near another fixed cylinder." Journal of Sound and Vibration 333, no. 10 (May 2014): 2863–80. http://dx.doi.org/10.1016/j.jsv.2014.01.007.

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Sun, Yun Ling, Sheng Jie Wang, and Hong Xiang Tian. "The Research on Weak Fault Time Domain Feature Extraction of Diesel Engine Instantaneous Speed." Applied Mechanics and Materials 687-691 (November 2014): 1026–29. http://dx.doi.org/10.4028/www.scientific.net/amm.687-691.1026.

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Instantaneous speed signal is a new information source for diesel fault diagnosis. It has been used in critical fault diagnosis successfully such as misfire. But the occurrence rate of early weak diesel fault is high, and can’t be diagnosed easily by other information source, so it has high value to research on the weak fault feature extraction method of transient speed. Due to the difficulty in setting up effect and accurate mathematic model for diesel engine instantaneous speed under weak fault conditions, so in this paper the early fault simulated experiments are proceed in 6-135 type diesels. Many early faults are simulated by adjusting cylinder fuel eject quantity, adjusting exhaust valve clearance, simulating exhaust valve leak in differ degree. Through analyzing the variation rule of instantaneous speed signal in different status, the direct time domain fault feature is extracted. It is the instantaneous speed unitary rise amplitude ratio of every cylinder, the value of each cylinder is named as Pi. The experiments outcome shows that if Pi descend over 10%, then the No.i cylinder exist fault. The feature is very sensitive to some fault which influence gas press in cylinder such as fuel ejects quantity not uniformity and valve leaking.

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Yao, Yuanzhao, Naoki Ikeda, Siti Chalimah, Takashi Kuroda, Yoshimasa Sugimoto, Takaaki Mano, Hiromi Koyama, et al. "Improved power and far-field pattern of surface-emitting quantum cascade lasers with strain compensation to operate at 4.3 μm." Japanese Journal of Applied Physics 61, no. 5 (April 19, 2022): 052001. http://dx.doi.org/10.35848/1347-4065/ac5dbb.

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Abstract We fabricated surface-emitting quantum cascade lasers with photonic crystal resonators whose active layers were strain-compensated InGaAs/AlInAs multiple quantum wells to operate at 4.3 μm. We tested two kinds of square-lattice photonic crystals consisting of circular and pentagonal InGaAs cylinders as a unit structure. We examined their output power and far-field pattern to find that both of them were improved by lowering the photonic-crystal symmetry to achieve a high extraction efficiency. The maximum output power was 50 mW at 77 K and the far-field pattern was a single peak with a divergence angle smaller than 1° for the pentagonal cylinder structure. In addition, we attributed the lasing mode to a B2-symmetric (quadrupole) eigenstate on the Γ point for the circular cylinder structure by observing the polarization dependence of the far-field pattern and comparing it with calculations by the k · p perturbation method.

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Rahman, Anas Abdul, Kumaran Rajendran, Ayu Abdul-Rahman, Gisrina Elin Suhri, and Lakshuman Dass. "Analysis of Wake Turbulence for a Savonius Turbine for Malaysia’s Slow-Moving Current Flow." International Journal of Renewable Energy Development 11, no. 4 (July 18, 2022): 1078–88. http://dx.doi.org/10.14710/ijred.2022.45985.

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With Malaysia being surrounded by water bodies, tidal energy could be used for energy extraction. While several turbine designs and technologies have been used for tidal energy extraction, information on the use of vertical-axis tidal turbines (VATTs) for shallow-water applications is scarce. However, implementing horizontal-axis tidal turbines (HATTs) is not feasible due to Malaysian ocean depths. Hence, examining the wake-flow characteristics of VATTs in a shallow water-working environment in Malaysia is essential. The wake turbulence of the Savonius turbine model was compared with that of a hypothetical ‘actuator' cylinder, a VATT representation. Subsequently, the wake turbulences of a Savonius turbine model in static and dynamic simulations were compared to understand the flow distinction. Compared with that exhibited by the hypothetical actuator cylinder of 2.5 m, the hypothetical actuator cylinder of 5 m exhibits greater velocity deceleration. Additionally, the modelled Savonius turbine exhibits significantly more deceleration than that exhibited by the hypothetical actuator cylinder. Finally, the analysis of the static model of the Savonius turbine shows deceleration that is greater than that of the dynamic model.

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Paré-Lambert, Olivier, and Mathieu Olivier. "A parametric study of energy extraction from vortex-induced vibrations." Transactions of the Canadian Society for Mechanical Engineering 42, no. 4 (December 1, 2018): 359–69. http://dx.doi.org/10.1139/tcsme-2017-0071.

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This paper presents a parametric investigation of an oscillating-cylinder turbine concept based on vortex-induced vibrations. The parametric space includes four parameters: the Reynolds number, the mass ratio, the dimensionless stiffness, and the dimensionless damping. The damping–stiffness space is explored for four different mass ratios at a fixed Reynolds number of 200. Also, the influence of the parameters on the amplitude of cylinder displacement and on the efficiency of power harnessing is discussed. Vortex-shedding patterns observed within the parametric space are investigated. The 2S, 2P, and C(2S) wake modes are observed and are related to turbine performance. Preliminary results show a maximum efficiency of 10.6%, which is obtained with low mass ratios.

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Inui, Masatomo, and Nobuyuki Umezu. "Extraction of vertical cylinder contacting area for motorcycle safety verification." Computer-Aided Design and Applications 15, no. 4 (January 5, 2018): 556–64. http://dx.doi.org/10.1080/16864360.2017.1419643.

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Singh, Kalpana, and Tapobrata Lahiri. "An Improved Protein Surface Extraction Method Using Rotating Cylinder Probe." Interdisciplinary Sciences: Computational Life Sciences 9, no. 1 (November 22, 2016): 65–71. http://dx.doi.org/10.1007/s12539-016-0201-8.

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Formentin, Simone, Matteo Corno, Daniel Alberer, Christian Benatzky, Luigi Del Re, and Sergio M. Savaresi. "NOx virtual sensor design via in-cylinder pressure feature extraction*." IFAC Proceedings Volumes 45, no. 16 (July 2012): 739–44. http://dx.doi.org/10.3182/20120711-3-be-2027.00309.

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Bhattacharya, Amitabh, and Shahajhan S. Sorathiya Shahajhan. "Power extraction from vortex-induced angular oscillations of elliptical cylinder." Journal of Fluids and Structures 63 (May 2016): 140–54. http://dx.doi.org/10.1016/j.jfluidstructs.2016.03.008.

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Wang, Xin Qing, Yang Zhao, Sheng Liang, and Shu Hua Qian. "Extraction of Frequency-Variable Characteristics and Analysis of Modulation Mechanism under Periodic Excitation." Applied Mechanics and Materials 141 (November 2011): 279–83. http://dx.doi.org/10.4028/www.scientific.net/amm.141.279.

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Free vibration of sealed hydraulic cylinder under periodic excitation has remarkable unstationary characteristics, e.g. quick change, wide frequency range and complex modulation. Combining with wavelet transform, Wigner-Ville distribution and Hilbert-Hang transform, the pressure signal of the hydraulic cylinder is decomposed, the free vibration component is extracted and re-composed, the frequency modulation characteristic is extracted and identified, and the modulation mechanism is discussed. It is demonstrated by comparison that HHT theory is effective for feature extraction and modulation analysis.

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Catania, A. E., and A. Mittica. "Extraction Techniques and Analysis of Turbulence Quantities From In-Cylinder Velocity Data." Journal of Engineering for Gas Turbines and Power 111, no. 3 (July 1, 1989): 466–78. http://dx.doi.org/10.1115/1.3240277.

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In addition to the frequently used statistical ensemble-average, non-Reynolds filtering operators have long been proposed for nonstationary turbulent quantities. Several techniques for the reduction of velocity data acquired in the cylinder of internal combustion reciprocating engines have been developed by various researchers in order to separate the “mean flow” from the “fluctuating motion,” cycle by cycle, and to analyze small-scale engine turbulence by statistical methods. Therefore a thorough examination of these techniques and a detailed comparison between them would seem to be a preliminary step in attempting a general study of unconventional averaging procedures for reciprocating engine flow application. To that end, in the present work, five different cycle-resolved data reduction methods and the conventional ensemble-average were applied to the same in-cylinder velocity data, so as to review and compare them. One of the methods was developed by the authors. The data were acquired in the cylinder of a direct-injection automotive diesel engine, during induction and compression strokes, using an advanced hot-wire anemometry technique. Correlation and spectral analysis of the engine turbulence, as determined from the data with the different procedures, were also performed.

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Selimefendigil, Fatih, Mondher Hamzaoui, Abdelkarim Aydi, Badr M. Alshammari, and Lioua Kolsi. "Hybrid Nano-Jet Impingement Cooling of Double Rotating Cylinders Immersed in Porous Medium." Mathematics 11, no. 1 (December 23, 2022): 51. http://dx.doi.org/10.3390/math11010051.

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A cooling system with impinging jets is used extensively in diverse engineering applications, such as solar panels, electronic equipments, battery thermal management, textiles and drying applications. Over the years many methods have been offered to increase the effectiveness of the cooling system design by different techniques. In one of the available methods, nano-jets are used to achieve a higher local and average heat transfer coefficient. In this study, convective cooling of double rotating cylinders embedded in a porous medium is analyzed by using hybrid nano-jets. A finite element formulation of the thermo-fluid system is considered, while impacts of Reynolds number, rotational speed of the double cylinders, permeability of the porous medium and distance between the cylinders on the cooling performance are numerically assessed. Hybrid and pure fluid performances in the jet cooling system are compared. It is observed that the cooling performance improves when the rotating speed of the cylinder, permeability of the medium and jet Reynolds number are increased. The heat transfer behavior when varying the distance between the cylinders is different for the first and second cylinder. Higher thermal performances are achieved when hybrid nanofluid with higher nanoparticle loading is used. An optimization algorithm is used for finding the optimum distance and rotational speeds of the cylinders for obtaining an improved cooling performance, while results show higher effectiveness as compared to a parametric study. The outcomes of the present work are useful for the thermal design and optimization of the cooling system design for configurations encountered in electronic cooling, energy extraction and waste heat recovery.

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Baulin, F. B., and E. V. Buryi. "Feature extraction techniques for LIDAR range profile based object recognition." Computer Optics 45, no. 6 (November 2021): 934–41. http://dx.doi.org/10.18287/2412-6179-co-891.

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The article provides an overview of range profile feature extraction methods used in laser iden-tification, detection and ranging systems. It also outlines feature selection methods and highlights their respective limitations. A novel feature selection method which maximizes Euclidian dis-tances between feature vectors is presented. The article also showcases advantages of the proposed technique by extracting features of basic objects (a sphere, a cone, and a cylinder). This method is shown to be effective when feature vector manifolds are not linearly separable due to the unknown viewing aspect of an object. The technique is also effective when feature vector manifolds overlap due to the different objects having similar range profiles.

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MARTINS-RIVAS, HERVÉ, and CHIANG C. MEI. "Wave power extraction from an oscillating water column at the tip of a breakwater." Journal of Fluid Mechanics 626 (May 10, 2009): 395–414. http://dx.doi.org/10.1017/s0022112009005990.

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To reduce the costs of construction, operation, maintenance, energy storage and grid connection, some devices for extracting energy from sea waves are likely to be installed on the coast. We study theoretically a single oscillating water column (OWC) installed at the tip of a long and thin breakwater. The linearized problems of radiation and scattering for a hollow cylinder with an open bottom are then solved by the usual method of eigenfunction expansions and integral equations. Since a thin breakwater is the limit of a wedge, an exact solution for the diffraction by a solid cylinder at the tip of a wedge is derived to facilitate the analysis. Following Sarmento & Falcão (J. Fluid Mech., vol. 150, 1985, pp. 467–485), power takeoff by Wells turbines is modelled by including air compressibility in the chamber above the water surface. The effects of air compressibility on the extraction efficiency is studied. It is shown that for this simple geometry the angle of incidence affects the waves outside the structure but not the extracted power.

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Na, Qi, Guosheng Feng, and Tixian Tian. "Real-Time Leak Detection in High Frequency Hydraulic Cylinder Based on Intelligent Control." Wireless Communications and Mobile Computing 2022 (September 25, 2022): 1–8. http://dx.doi.org/10.1155/2022/4753328.

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Most of the existing hydraulic cylinder internal leakage detection methods are laboratory testing methods, mainly the pressure-holding method, measurement of hydraulic cylinder settlement method, and measuring cup measurement method. The internal leakage of the hydraulic cylinder affects the damping characteristics of the control system. Therefore, real-time internal leakage detection plays an important role in the control characteristics. This paper first proposes a wavelet analysis-based extraction of hydraulic cylinder internal leakage fault eigenvalues for analysis, that is, data processing. A convolutional neural network-based detection method is also proposed, in which the pressure signal of a chamber of a hydraulic cylinder is first obtained through simulation under four operating conditions: no leakage, small leakage, medium leakage, and large leakage. Compared to traditional modelling methods, the method overcomes the difficulties in modelling nonlinear hydraulic systems, requires only pressure signal acquisition, is simple and reliable, and is compared with traditional BP neural networks to demonstrate its superiority.

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Gopalkrishnan, R., M. S. Triantafyllou, G. S. Triantafyllou, and D. Barrett. "Active vorticity control in a shear flow using a flapping foil." Journal of Fluid Mechanics 274 (September 10, 1994): 1–21. http://dx.doi.org/10.1017/s0022112094002016.

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It is shown experimentally that free shear flows can be substantially altered through direct control of the large coherent vortices present in the flow.First, flow-visualization experiments are conducted in Kalliroscope fluid at Reynolds number 550. A foil is placed in the wake of a D-section cylinder, sufficiently far behind the cylinder so that it does not interfere with the vortex formation process. The foil performs a heaving and pitching oscillation at a frequency close to the Strouhal frequency of the cylinder, while cylinder and foil also move forward at constant speed. By varying the phase of the foil oscillation, three basic interaction modes are identified. (i) Formation of a street of pairs of counter-rotating vortices, each pair consisting of one vortex from the initial street of the cylinder and one vortex shed by the foil. The width of the wake is then substantially increased. (ii) Formation of a street of vortices with reduced or even reverse circulation compared to that of oncoming cylinder vortices, through repositioning of cylinder vortices by the foil and interaction with vorticity of the opposite sign shed from the trailing edge of the foil. (iii) Formation of a street of vortices with circulation increased through merging of cylinder vortices with vortices of the same sign shed by the foil. In modes (ii) and (iii) considerable repositioning of the cylinder vortices takes place immediately behind the foil, resulting in a regular or reverse Kármán street. The formation of these three interaction patterns is achieved only for specific parametric values; for different values of the parameters no dominant stable pattern emerges.Subsequently, the experiments are repeated in a different facility at larger scale, resulting in Reynolds number 20000, in order to obtain force and torque measurements. The purpose of the second set of experiments is to assess the impact of flow control on the efficiency of the oscillating foil, and hence investigate the possibility of energy extraction. It is found that the efficiency of the foil depends strongly on the phase difference between the oscillation of the foil and the arrival of cylinder vortices. Peaks in foil efficiency are associated with the formation of a street of weakened vortices and energy extraction by the foil from the vortices of the vortex street.

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Sulym, Heorgij, Imre Timar, and Ihor Turchyn. "Transient Vibrations of an Elastic Cylinder Inserted in the Elastic Medium." Acta Mechanica et Automatica 10, no. 2 (June 1, 2016): 133–36. http://dx.doi.org/10.1515/ama-2016-0021.

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Abstract Using method of Laguerre polynomials we have obtained the solution of the dynamic problem of the theory of elasticity for elastic cylinder inserted into massive body modeled as a space. The source of non-stationary processes in composite is high intensity force load of the inner surface of the cylinder. On the surface separation of materials of space and cylinder the conditions of ideal mechanical contact are satisfied. The solution is obtained as series of Laguerre polynomials, which coefficients are found from recurrent relations. The results of numerical analysis of transient stress-strain state in elastic space with cylindrical insertion might be used for the technological process of hydraulic fracturing during shale gas extraction.

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Podulka, Przemysław. "Analysis of dimples distribution in surface topography measurements." Mechanik 91, no. 11 (November 12, 2018): 984–87. http://dx.doi.org/10.17814/mechanik.2018.11.176.

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In this paper the influence of distribution of oil pockets on areal form removal in surface topography measurement was taken into consideration. Surface topography of plateau-honed cylinder liners with burnished oil pockets was analyzed. The effect of dimples distribution on surface topography parameters (from ISO 25178 standard) after form removal by commonly used algorithms (cylinder fitted by the least square method, polynomials of nth degree, robust Gaussian filter) and/or other procedures (plateau-part filtering method, digital extraction of valleys) was taken into account.

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Bi, Fengrong, Teng Ma, Jian Zhang, Lin Li, and Chunfang Shi. "Knock Detection in Spark Ignition Engines Base on Complementary Ensemble Empirical Mode Decomposition-Hilbert Transform." Shock and Vibration 2016 (2016): 1–17. http://dx.doi.org/10.1155/2016/9507540.

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In spark ignition engines, knock onset limits the maximum spark advance. An inaccurate identification of this limit penalises the fuel conversion efficiency. Thus knock feature extraction is the key of closed-loop control of ignition in spark ignition engine. This paper reports an investigation of knock detection in spark ignition (SI) engines using CEEMD-Hilbert transform based on the engine cylinder pressure signals and engine cylinder block vibration signals. Complementary Ensemble Empirical Mode Decomposition (CEEMD) was used to decompose the signal and detect knock characteristic. Hilbert transform was used to analyze the frequency information of knock characteristic. The result shows that, for both of cylinder pressure signals and vibration signals, the CEEMD algorithm could extract the knock characteristic, and the Hilbert transform result shows that the energy of knock impact areas has the phenomenon of frequency concentration in both cylinder pressure signal and cylinder block vibration signal. At last, the knock window is then determined, based on which a new knock intensity evaluation factorKis propose, and it can accurately distinguish between heavy knock, light knock, and normal combustion three states.

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Siregar, A. N., J. A. Ghani, C. H. C. Haron, M. Rizal, Z. Yaakob, and S. K. Kamarudin. "Comparison of oil press for jatropha oil – a review." Research in Agricultural Engineering 61, No. 1 (June 2, 2016): 1–13. http://dx.doi.org/10.17221/22/2013-rae.

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As petrol will soon be exhausted in the near future, Jatropha is going to be one of the substitute candidates for future biodiesel production. Countries of South-East Asia, such as Malaysia, they are going to start the establishment of Jatropha plantations assuming that Jatropha will be the main resource for biodiesel production. A press is commonly used to extract oils from Jatropha. An oil press can be manually driven or engine-powered. In this paper, we will review some available advances focused on mechanical extraction techniques, covering three types of press for Jatropha oil extraction. We have found that major points like operating principles, oil extraction levels, advantages and disadvantages of each press and important factors to increase oil recovery. Based on the study, three types of press are: ram press, which is ineffective; strainer press, which is able to produce more oil than others and cylinder-hole press, which is the best due to its capacity in extracting oil from Jatropha seeds for about 89.4% of oil yields.

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Deng, Yaohua, WeiJie Li, ShengYu Lin, Qiwen Lu, and Xiali Liu. "Detection method of water channel defects in engine block based on deep learning." Journal of Physics: Conference Series 2366, no. 1 (November 1, 2022): 012020. http://dx.doi.org/10.1088/1742-6596/2366/1/012020.

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Abstract Aiming at the low efficiency of manual detection in the detection of water channel defects of engine cylinder block and the poor generalization ability of traditional machine vision in manual design features, an improved water channel defect detection model of cylinder block based on fast RCNN network is proposed. Restnet50 is selected as the feature extraction network of waterway defects, and feature pyramid network (FPN) is introduced to improve the detection ability of small defects; The anchor box is optimized by k-means++ clustering algorithm to improve the positioning of the target box. Experiments show that the map of the improved network in the engine cylinder block waterway defect data set reaches 88.74%, the accuracy is increased by 4% compared with the original fast RCNN, and the recall rate is increased by 1.67%. The recognition and detection effect in real samples is good, and it can be effectively used for the engine cylinder block waterway defect detection.

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Darma, Darma. "Performance Test of Various Teeth Diameter of Cylinder Type Sago Rasping Machine." Jurnal Keteknikan Pertanian 8, no. 3 (March 5, 2021): 113–22. http://dx.doi.org/10.19028/jtep.08.3.113-122.

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Traditional method of sago starch extraction was a time and labor intensive process. The most laborious stage is pith disintegration which is done by using hammer-like tools called pounder. However, the use of rasping machine to disintegrate the pith is saving time and energy significantly. The objective of this study was to investigate the effect of teeth diameter and cylinder rotation speed on performance of cylinder type sago rasping machine. In the experiment, four variations of teeth diameter i.e. 3mm, 4 mm, 5 mm and 6 mm, and three levels of cylinder rotation speed i.e. 1500 rpm, 2000 rpm and 2500 rpm were examined. Results showed that both teeth diameter and cylinder rotation speed significantly affect the rasping capacity. Likewise teeth diameter also significantly affect on starch percentage and starch losses in waste. Meanwhile, cylinder rotation speed and the interaction of the two factors have no significant effect on the starch percentage and starch loss in waste. The highest performance was obtained at the condition of teeth diameter 3 mm with cylinder rotation speed of 2500 rpm. The performance of the machine at the condition were (a) rasping capacity 2282 kg h-1, (b) starch percentage 33.02 %, (wb), (c) starch loss in waste 8.77 %.

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Wang, Yizhe, Cunqian Feng, Yongshun Zhang, and Sisan He. "Space Precession Target Classification Based on Radar High-Resolution Range Profiles." International Journal of Antennas and Propagation 2019 (February 27, 2019): 1–9. http://dx.doi.org/10.1155/2019/8151620.

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Precession is a common micromotion form of space targets, introducing additional micro-Doppler (m-D) modulation into the radar echo. Effective classification of space targets is of great significance for further micromotion parameter extraction and identification. Feature extraction is a key step during the classification process, largely influencing the final classification performance. This paper presents two methods for classifying different types of space precession targets from the HRRPs. We first establish the precession model of space targets and analyze the scattering characteristics and then compute electromagnetic data of the cone target, cone-cylinder target, and cone-cylinder-flare target. Experimental results demonstrate that the support vector machine (SVM) using histograms of oriented gradient (HOG) features achieves a good result, whereas the deep convolutional neural network (DCNN) obtains a higher classification accuracy. DCNN combines the feature extractor and the classifier itself to automatically mine the high-level signatures of HRRPs through a training process. Besides, the efficiency of the two classification processes are compared using the same dataset.

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Liu, Xiao, Tianxiang Jing, Dequan Xuan, Shixiong Hu, Yong Li, and Sen Xu. "Morphological Characteristics of Hydraulic Flushing under Multifactor Coupling and Its Enlightenment." Geofluids 2022 (July 18, 2022): 1–13. http://dx.doi.org/10.1155/2022/2548448.

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The shape of the hydraulic flushing hole is an important basis to determine the effective pumping radius. In the design and evaluation of the drilling hole, it is usually equivalent to a cylinder. However, the formation of the shape of the hole is affected by the gravity of coal and rock bulk, the friction of coal and rock, water force, stress, and other factors, so the scientific nature that is equivalent to a cylinder remains to be discussed. In this paper, based on the analysis of the whole process of hydraulic flushing and the formation of the pore shape, gravity, friction, water force, and ground stress of coal and rock bulk are selected as important factors affecting the pore shape, and the parallel Bergmark-Roos equation and PKN model are introduced to establish the BR-PKN equation of the pore shape of hydraulic flushing. MATLAB is used to reproduce the shape of the hydraulic flushing hole, which is a kind of ellipsoid with three different axes. In order to verify the accuracy of the hole shape, the YZD18.5 video imaging logging tool for mine lateral resistivity is used to collect and analyze the shape data of the hydraulic flushing hole, and the hole section is drawn, which is basically consistent with the theoretical derivation of the hydraulic flushing hole shape. COMSOL is used to simulate the hydraulic flushing equivalent of the ellipsoid hole compared with the cylinder hole under the same coal output and extraction time of 90 days. The extraction radius, desorption surface area, and effective extraction volume are 0.95, 0.79, and 1.14 times, respectively, providing a basis for the optimal design of hydraulic flushing.

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Yao, Zhu Ting, and Hong Xia Pan. "The Engine Fault Diagnosis Based on Time Domain and Frequency Domain." Advanced Materials Research 936 (June 2014): 2243–46. http://dx.doi.org/10.4028/www.scientific.net/amr.936.2243.

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Engine is as a power machine, the operating status is good or bad, directly affects the working status of equipment. The status monitoring and fault diagnosis is very necessary to ensure that the equipment runs in its best, and improves equipment maintenance quality and efficiency. The engine failure shows the complexity and diversity of the interaction and complex relationship between the various subsystems of the engine, that is the fault of complexity, ambiguity, correlation, relativity and multiple faults coexistence. The available information are much in the engine diagnosis, for example, the vibration signal from bearings, cylinder head or cylinder block surface; oil, cooling water, pressure of intake, exhaust and fuel; temperature signal; noise, speed or oil-sample signals. In this paper, an engine as an example, engine fault diagnosis experimental system is built, the normal state, left one and right six cylinders off the oil, air filter blockage (inlet wood blockage is 30%, the inlet has screen cloth.) in the load of 2565Nm, and the speeds of 1500r/min, 1800r/min, 2200r/min are studied. The experimental results analysis, feature extraction and fault diagnosis are finished based on the time domain and frequency domain. Keywords: engine, fault diagnosis, time domain, frequency domain.

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Vurgaft, Amit, Shai B. Elbaz, and Amir D. Gat. "Forced motion of a cylinder within a liquid-filled elastic tube – a model of minimally invasive medical procedures." Journal of Fluid Mechanics 881 (October 29, 2019): 1048–72. http://dx.doi.org/10.1017/jfm.2019.789.

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This work analyses the viscous flow and elastic deformation created by the forced axial motion of a rigid cylinder within an elastic liquid-filled tube. The examined configuration is relevant to various minimally invasive medical procedures in which slender devices are inserted into fluid-filled biological vessels, such as vascular interventions, interventional radiology, endoscopies and laparoscopies. By applying the lubrication approximation, thin shell elastic model, as well as scaling analysis and regular and singular asymptotic schemes, the problem is examined for small and large deformation limits (relative to the gap between the cylinder and the tube). At the limit of large deformations, forced insertion of the cylinder is shown to involve three distinct regimes and time scales: (i) initial shear dominant regime, (ii) intermediate regime of dominant fluidic pressure and a propagating viscous-peeling front, (iii) late-time quasi-steady flow regime of the fully peeled tube. A uniform solution for all regimes is presented for a suddenly applied constant force, showing initial deceleration and then acceleration of the inserted cylinder. For the case of forced extraction of the cylinder from the tube, the negative gauge pressure reduces the gap between the cylinder and the tube, increasing viscous resistance or creating friction due to contact of the tube and cylinder. Matched asymptotic schemes are used to calculate the dynamics of the near-contact and contact limits. We find that the cylinder exits the tube in a finite time for sufficiently small or large forces. However, for an intermediate range of forces, the radial contact creates a steady locking of the cylinder inside the tube.

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Darma, Darma, Reniana Reniana, and Arbianto Arif Moh. "UJI LAPANG MESIN PENGOLAHAN SAGU PRODUKSI BENGKEL PERMESINAN AGROINDUSTRI UNIVERSITAS PAPUA." Jurnal Teknik Pertanian Lampung (Journal of Agricultural Engineering) 9, no. 3 (September 30, 2020): 191. http://dx.doi.org/10.23960/jtep-l.v9i3.191-200.

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Papua and West Papua Province have the large potential of sago palm (Metroxylon sagu), however, until now the production and utilization is very low compared with its potential. This is because of most farmers in this area still use traditional method in processing sago. The traditional method is labour intensive and time consuming process. Sago farmers in this area still apply traditional ways to process sago starch due to the lack of processing machines. The objective of this research was to conduct field testing of sago processing machine produced by Agroindustry Machinery Workshop of Papua University. The machines that have been tested consist of cylinder type sago rasping machine and stirrer rotary blade sago starch extraction machine. The machine’s performance under field condition was evaluated by measuring parameters (a) rasping capacity, (b) extraction capacity, (c) starch percentage, (d) starch yield and (e) starch loss in waste. Results showed that all parts of the machine are functioning properly and farmers can easily operate the machine. The performances of the machines under field condition were (a) rasping capacity 1,159. 8 kg/hour, (b) extraction capacity 243.8 kg/hour, (c) starch percentage 38.26 %, (d) starch yield 93 kg/hour and (e) starch loss in waste 1.03 %. Keywords: cylinder type, field test, rasping machine, sago processing, starch percentage

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Weymouth, G. D. "Chaotic rotation of a towed elliptical cylinder." Journal of Fluid Mechanics 743 (March 6, 2014): 385–98. http://dx.doi.org/10.1017/jfm.2014.42.

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AbstractIn this paper I consider the self-excited rotation of an elliptical cylinder towed in a viscous fluid as a canonical model of nonlinear fluid–structure interactions with possible applications in the design of sensors and energy extraction devices. First, the self-excited ellipse system is shown to be analogous to the forced bistable oscillators studied in classic chaos theory. A single variable, the distance between the pivot and the centroid, governs the system bifurcation into bistability. Next, fully coupled computational fluid dynamics simulations of the motion of the cylinder demonstrate limit cycle, period doubling, intermittently chaotic and fully chaotic dynamics as the distance is further adjusted. The viscous wake behind the cylinder is presented for the limit-cycle cases and new types of stable wakes are characterized for each. In contrast, a chaotic case demonstrates an independence of the wake and structural states. The rotational kinetic energy is quantified and correlated to the vortex shedding and the trajectory periodicity. Chaotic and high-period system responses are found to persist when structural damping is applied and for Reynolds numbers as low as 200.

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Ma, Leixin. "Interpretable machine learning for insight extraction from rigid cylinder flow-induced vibration phenomena." Applied Ocean Research 119 (February 2022): 102975. http://dx.doi.org/10.1016/j.apor.2021.102975.

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Soti, Atul Kumar, and Ashoke De. "Vortex-induced vibrations of a confined circular cylinder for efficient flow power extraction." Physics of Fluids 32, no. 3 (March 1, 2020): 033603. http://dx.doi.org/10.1063/1.5131334.

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Rochussen, Jeremy, and Patrick Kirchen. "Robust image segmentation for feature extraction from internal combustion engine in-cylinder images." Measurement Science and Technology 32, no. 1 (January 1, 2020): 015302. http://dx.doi.org/10.1088/1361-6501/abae8f.

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Podulka, Przemysław. "Proposals of Frequency-Based and Direction Methods to Reduce the Influence of Surface Topography Measurement Errors." Coatings 12, no. 6 (May 25, 2022): 726. http://dx.doi.org/10.3390/coatings12060726.

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Various methods, based on both surface frequency and direction, can be alternatively proposed to reduce the influence of high-frequency measurement and data analysis errors. Various types of details were studied, e.g., cylinder liners after the plateau-honing process, plateau-honed cylinder liners with additionally burnished oil pockets (dimples), turned, ground, milled or laser-textured. They were measured with stylus or non-contact (optic) techniques. It was suggested to support various frequency-based methods, e.g., Frequency Spectrum, Power Spectral Densities or Autocorrelation Function, with direction techniques to provide reduction of errors in both detection and extraction of high-frequency measurement errors. Results can be especially valuable for regular studies when frequency-based measurement errors are difficult to be identified.

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Le, T. T., J. Watton, and D. T. Pham. "Fault classification of fluid power systems using a dynamics feature extraction technique and neural networks." Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering 212, no. 2 (March 1, 1998): 87–97. http://dx.doi.org/10.1243/0959651981539325.

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Multilayer perceptron (MLP) type neural networks and dynamic feature extraction techniques, namely linear prediction coding (LPC) and LPC cepstrum, are used to classify leakage type and to predict leakage flowrate magnitude in an electrohydraulic cylinder drive. Both single-leakage and multiple-leakage type faults are considered. A novel feature is that only pressure transient responses are employed as information. In addition, the feature extraction technique used to detect faults can result in a large data dimensionality reduction. The performance of two MLP models, namely serial and parallel, are studied to reflect the importance of the way data are presented to the MLP.

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Zabihi-Hesari, Alireza, Saeed Ansari-Rad, Farzad A. Shirazi, and Moosa Ayati. "Fault detection and diagnosis of a 12-cylinder trainset diesel engine based on vibration signature analysis and neural network." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 233, no. 6 (June 3, 2018): 1910–23. http://dx.doi.org/10.1177/0954406218778313.

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This paper presents a condition monitoring and combustion fault detection technique for a 12-cylinder 588 kW trainset diesel engine based on vibration signature analysis using fast Fourier transform, discrete wavelet transform, and artificial neural network. Most of the conventional fault diagnosis techniques in diesel engines are mainly based on analyzing the difference of vibration signals amplitude in the time domain or frequency spectrum. Unfortunately, for complex engines, the time- or frequency-domain approaches do not provide appropriate features solely. In the present study, vibration signals are captured from both intake manifold and cylinder heads of the engine and were analyzed in time-, frequency-, and time–frequency domains. In addition, experimental data of a 12-cylinder 588 kW diesel engine (of a trainset) are captured and the proposed method is verified via these data. Results show that power spectra of vibration signals in the low-frequency range reliably distinguish between normal and faulty conditions. However, they cannot identify the fault location. Hence, a feature extraction method based on discrete wavelet transform and energy spectrum is proposed. The extracted features from discrete wavelet transform are used as inputs in a neural network for classification purposes according to the location of sensors and faults. The experimental results verified that vibration signals acquired from intake manifold have more potential in fault detection. In addition, the capacity of discrete wavelet transform and artificial neural network in detection and diagnosis of faulty cylinders subjected to the abnormal fuel injection was revealed in a complex diesel engine. Beside condition monitoring of the engine, a two-step fault detection method is proposed, which is more reliable than other one-step methods for complex engines. The average condition monitoring performance is from 93.89% up to 99.17%, based on fault location and sensor placement, and the minimum classification performance is 98.34%.

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Aniszewska, Monika, Ewa Tulska, and Katarzyna Żurawska. "Variability of cone parameters and scale morphology in the black alder (Alnus glutinosa L.) in the context of seed extraction." European Journal of Forest Research 138, no. 6 (September 9, 2019): 981–89. http://dx.doi.org/10.1007/s10342-019-01218-x.

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Abstract In this paper, the results of research on the variability of black alder cones (Alnus glutinosa L.) ware presented. The research was carried out for two, significantly different, batches of cones. Basic size parameters and mass were measured. The shape of the cone was determined, and it was described with the fourth-degree polynomial. The surface area and volume of the cone were calculated using the forming curve and formulas for solids: barrel and cylinder. The parameters of cones—shape surface area and volume—were analyzed. It was found that for alder cones (from the researched origins), the average volumes calculated from the barrel formula are 1701 mm3 and 1162 mm3, and the areas calculated from the cylinder formula are 807 mm2 and 597 mm2. The structure of the inner and outer sides of scales was examined using a scanning electron microscope. Using the MultiScanBase v. 18.03 program, the elements of husk structure that could affect the efficiency of seeds extraction were measured. The results of the research can be used to program the process of seeds extraction from alder cones in commercial installations.

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Taneri, Suphi, Saskia Kießler, Anika Rost, Tim Schultz, and H. Burkhard Dick. "Clinical outcomes of small incision lenticule extraction versus advanced surface ablation in low myopia." European Journal of Ophthalmology 30, no. 6 (July 26, 2019): 1278–86. http://dx.doi.org/10.1177/1120672119865699.

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Purpose: To compare the visual and refractive outcomes of small incision lenticule extraction and advanced surface ablation for low myopia or myopic astigmatism. Methods: Retrospective, observational case series of our first 50 consecutive small incision lenticule extraction patients compared to refraction-matched 50 advanced surface ablation treatments with attempted spherical equivalent correction ⩽−3.5 D, astigmatism ⩽−1.5 D, and corrected distance visual acuity of 1.0 (decimal scale) or better. Only one eye per patient was included. Results: Small incision lenticule extraction: mean attempted spherical equivalent correction was −2.80 ± 0.63 D. Uncorrected distance visual acuity was 0.85 and 1.0 at days 1 and 5, respectively. At 3 months, mean spherical equivalent refraction was 0.02 ± 0.32 D (range: −0.5 to +0.75 D), mean cylinder was −0.24 ± 0.21 D (range: 0 to −0.75 D), mean uncorrected distance visual acuity was 1.27, mean efficacy index was 0.96, and mean safety index was 1.05. Uncorrected distance visual acuity was same or better than corrected distance visual acuity in 96%, astigmatism ⩽0.5 D in 98% and ⩽1 D in 100% of eyes, respectively. Advanced surface ablation: mean attempted spherical equivalent correction was −2.75 ± 0.5 D. Uncorrected distance visual acuity was 0.72 and 0.61 at days 1 and 5, respectively. At 3 months, mean spherical equivalent refraction was 0.22 ± 0.32 D, mean cylinder was −0.27 ± 0.27 D, mean uncorrected distance visual acuity was 1.21, mean efficacy index was 1.03, and mean safety index was 1.08. Conclusion: Small incision lenticule extraction for low myopia was found to be safe and effective with outcomes at 3 months similar to those obtained with advanced surface ablation while offering a quicker visual recovery.

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Zhang, Pan, Wenzhi Gao, Yong Li, and Yanjun Wang. "Misfire detection of diesel engine based on convolutional neural networks." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 235, no. 8 (January 11, 2021): 2148–65. http://dx.doi.org/10.1177/0954407020987077.

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With the ever-stringent vehicles exhaust emission standard and higher requirements on on-board diagnostic technology, the importance of misfire detection in vehicle emission control is emerging. The performance of a traditional misfire detection algorithm predominantly depends on the features and classifier selected. Fixed and handcrafted features require either a reliable dynamic model of an engine or a large number of experiment data to define the threshold, and then, form a map. Since convolutional neural networks (CNNs) have an inherent adaptive design and integrate the feature extraction with classification functions into a compact learning framework, the misfire fault-sensitive features can be auto-discovered from raw speed signals. Furthermore, CNNs can detect the fault features of the misfire through network training with fewer engine operating conditions. In this paper, the theory and method of the misfire diagnosis based on CNNs are presented. The experimental data for network training and testing are sampled on a six-cylinder inline diesel engine. The misfire patterns containing every one-cylinder and two-cylinder misfire are tested under the wide speed and load conditions of the engine. The results show that when the engine operates under steady-state conditions, one-cylinder or two-cylinder complete misfires can be detected accurately by CNNs. In addition, one-cylinder partial misfire is employed to examine the adaptability of trained 1-D CNN. It turns out that when the partial misfire reaches the same level as half amount of the normal fuel injection quantity, one-cylinder partial misfire can be detected with accuracy more than 96%. At last, the misfire detection under the non-stationary conditions, such as acceleration or deceleration, is conducted. The results show the 1-D CNN performed well in a limited acceleration range, and network failure occurs when the absolute acceleration of the engine speed is more than 100 r/min/s.

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Li, Yiqing, Wen Zhou, and Yanyang Zi. "A graphic pattern feature-mapping-based data-driven condition monitoring method for diesel engine malfunction identification and classification." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 233, no. 1 (February 5, 2018): 202–12. http://dx.doi.org/10.1177/0954406218755186.

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Effective condition monitoring of diesel engine can ensure the reliability of large-power machines and prevent catastrophic consequences. Cylinder pressure is capable of reflecting the whole combustion process of diesel engine, and hence can help to identify the malfunctions of the diesel engine during operation. In this paper, a graphic pattern feature-mapping method is proposed for graphic pattern feature recognition in data-driven condition monitoring. The graphic feature extraction and recognition are linked by labeled feature-mapping. It is used for identifying the running condition of the diesel engine via analyzing the cylinder pressure signal of the diesel engine. The different types of the malfunctions which are caused by different parts of the diesel engine such as induction system, valve actuating mechanism, fuel system, fuel injection system, etc. can be identified just by cylinder pressure signal. The bench experiment of a large-power diesel engine is performed to validate this graphic pattern recognition method. The results show that it has good accuracy on multi-malfunction identification and classification when the engine operates at one speed and one load.

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Kasten, Jens, Christoph Petz, Ingrid Hotz, Hans-Christian Hege, Bernd R. Noack, and Gilead Tadmor. "Publisher's Note: “Lagrangian feature extraction of the cylinder wake” [Phys. Fluids 22, 091108 (2010)]." Physics of Fluids 22, no. 10 (October 2010): 109901. http://dx.doi.org/10.1063/1.3507261.

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Chen, Minxuan, Tingliang Xie, and Cong Xu. "Continuous counter-current centrifugal extraction column with high throughput using a spiral inner cylinder." Chemical Engineering and Processing - Process Intensification 125 (March 2018): 1–7. http://dx.doi.org/10.1016/j.cep.2017.12.016.

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Dinculescu, Daniel, and Vasile Lavric. "Mathematical Model of the Liquid Membrane Extractive Column. Sensitivity to Operating Parameters." Revista de Chimie 59, no. 3 (April 9, 2008): 336–45. http://dx.doi.org/10.37358/rc.08.3.1759.

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The extraction-back extraction column of low concentration species by means of an organic closed loop flow, considered as liquid membrane, was modelled then simulated, using some simplifying assumptions. The main hypotheses are: the aqueous phase is perfectly mixed, the drops of the organic phase are lumped into a plug-flow inner cylinder co-axial with the aqueous phase, and the organic phases under the sieve and on the top of the column are perfectly mixed also. The dynamic model of the extraction-back extraction column is, then, applied to the recovery of the hydrocarboxylic acids. The mathematical model, reduced through orthogonal collocation to a system of ordinary differential equations, was solved using a self-adaptive (RK)-type method. Its validation was done based on batch experimental data; the optimal model parameters (the specific mass transfer coefficients for both extraction and back-extraction zones), ensuring the agreement with the experiment, were found by means of a modified genetic algorithm technique. Then, a sensitivity analysis was done, to grasp the behaviour of the system with respect to the main operating parameters - the organic flow in the closed loop, the partition coefficient and the buffer volume.

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Shi, Jiakui, Kun Yao, Junfeng Fu, Guoteng Ju, Fengjun Li, and Jie Wan. "Study on Early Warning Method of Cylinder Block's Off-Center Position and Swing Failure for 50 MW Steam Turbine." Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University 38, no. 6 (December 2020): 1308–15. http://dx.doi.org/10.1051/jnwpu/20203861308.

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Due to the special structure of the cylinder block, there is an off-center position and swing fault in the process of start-up and operation of the 50 MW extraction unit. Moreover, the lack of effective monitoring and early warning means seriously affects the safety of the unit operation. Therefore, it is very important to forewarn the fault of cylinder off-center position and swing. First of all, through the design of cylinder block offset amplifying mechanism for fault monitoring, the data of eccentric swing required for establishing mathematical model is obtained. Then, neural network is selected for data-driven modeling, two time series prediction models are obtained, and the influence of input and output parameters on the prediction accuracy is studied. Finally, by selecting reasonable early warning value and decision rules, an effective early warning of off-center position and swing fault is realized, and a monitoring device for real-time monitoring and fault early warning is developed. The actual application effect shows that this early warning method has important engineering value to avoid equipment damage caused by the swing fault for 50 MW unit.

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Journal articles on the topic 'Cylinder extraction'

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