A novel three-dimensional wheel–rail contact geometry method in the switch panel considering variable cross-sections and yaw angle

2021 ◽  
pp. 1-24
Author(s):  
Yu Chen ◽  
Jian Wang ◽  
Jiayin Chen ◽  
Ping Wang ◽  
Jingmang Xu ◽  
...  
Author(s):  
Hong Zhou ◽  
Kwun-Lon Ting

A three-dimensional wide curve is a spatial curve with variable cross sections. This paper introduces a geometric synthesis method for spatial compliant mechanisms by using three-dimensional wide curves. In this paper, every connection in a spatial compliant mechanism is represented by a three-dimensional wide curve and the whole spatial compliant mechanism is modeled as a set of connected three-dimensional wide curves. The geometric synthesis of a spatial compliant mechanism is considered as the generation and optimal selection of control parameters of the corresponding three-dimensional parametric wide curves. The deformation and performance of spatial compliant mechanisms are evaluated by the isoparametric degenerate-continuum nonlinear finite element procedure. The problem-dependent objectives are optimized and the practical constraints are imposed during the optimization process. The optimization problem is solved by the MATLAB constrained nonlinear programming algorithm. The effectiveness of the proposed geometric procedures is verified by the demonstrated examples.


2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Hong Zhou ◽  
Kwun-Lon Ting

A three-dimensional wide curve is a spatial curve with variable cross sections. This paper introduces a geometric optimization method for spatial compliant mechanisms by using three-dimensional wide curves. In this paper, every material connection in a spatial compliant mechanism is represented by a three-dimensional wide curve and the whole spatial compliant mechanism is modeled as a set of connected three-dimensional wide curves. The geometric optimization of a spatial compliant mechanism is considered as the generation and optimal selection of the control parameters of the corresponding three-dimensional parametric wide curves. The deformation and performance of spatial compliant mechanisms are evaluated by the isoparametric degenerate-continuum nonlinear finite element procedure. The problem-dependent objectives are optimized and the practical constraints are imposed during the optimization process. The optimization problem is solved by the MATLAB constrained nonlinear programming algorithm.


2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Hong Zhou ◽  
Kwun-Lon Ting

A 3D multilayer wide curve is a spatial curve with variable cross sections and multiple materials. The performance of multimaterial compliant mechanisms and structures is enhanced by integrating multiple materials into one-piece configurations. This paper introduces a geometric modeling method for spatial multimaterial compliant mechanisms and structures by using 3D multilayer wide curves. Based on the introduced modeling method, a geometric synthesis approach is proposed. In this paper, every connection in a spatial multimaterial compliant mechanism or structure is represented by a 3D multilayer wide curve and the whole compliant mechanism or structure is modeled as a set of connected wide curves. The geometric modeling and synthesis are considered as the generation and optimization of the control parameters of the corresponding 3D multilayer wide curves. The performance of spatial multimaterial compliant mechanisms and structures is evaluated by the isoparametric degenerate-continuum nonlinear finite element procedure. The problem-dependent objectives are optimized and the practical constraints are imposed during the synthesis process. The effectiveness of the proposed geometric modeling and synthesis procedures is verified by the demonstrated examples.


Author(s):  
Hong Zhou ◽  
Kwun-Lon Ting

Three-dimensional multilayer wide curves are spatial curves with variable cross sections and multiple materials. This paper introduces a geometric optimization method for spatial multimaterial compliant mechanisms and structures by using three-dimensional multilayer wide curves. In this paper, every multimaterial connection is represented by a three-dimensional multilayer wide curve and the whole spatial multimaterial compliant mechanism or structure is modeled as a set of connected three-dimensional multilayer wide curves. The geometric optimization of a spatial multimaterial compliant mechanism or structure is considered as the optimal selection of control parameters of the corresponding three-dimensional multilayer wide curves. The deformation and performance of spatial multimaterial compliant mechanisms and structures are evaluated by the isoparametric degenerate-continuum nonlinear finite element procedure. The problem-dependent objectives are optimized and the practical constraints are imposed during the optimization process. The optimization problem is solved by the MATLAB constrained nonlinear programming algorithm. The effectiveness of the proposed geometric optimization procedure is verified by the demonstrated examples.


2014 ◽  
Vol 565 ◽  
pp. 152-155
Author(s):  
A.V. Malozemov ◽  
Sergey N. Kharlamov

In this paper the structure is investigated of three-dimensional flows of rheological complex media (water-oil mixtures) in pipes and channels with long and short sections of constant and variable cross-sections. This is operating units of equipment for the oil and gas industry and power engineering. The steady and unsteady modes flows are modeling of oil-water environments in the internal systems. The ability analyzed of a low-viscosity two-phase structure of the movement to regroup in the peripheral region of the pipe wall with a higher shear stress. We study the pattern of change: coefficient of friction reducing its relatively high viscosity of the nucleus by forming a water ring, local hydrodynamic parameters for complex mixtures flow. The mechanisms are obtained of the influence of flow regimes on the phase boundary. Marked parts modeling of flow profile with immiscible phases within the system full equations of two-phase flow dynamics with allowance for the effects of interfacial interaction. The particular boundary conditions discussed for these flows. The reliability calculation estimated by comparison with the existing data of similar flows (for example, A.Wegmann and P.R. Rohr’s results).


2012 ◽  
Vol 9 (1) ◽  
pp. 94-97
Author(s):  
Yu.A. Itkulova

In the present work creeping three-dimensional flows of a viscous liquid in a cylindrical tube and a channel of variable cross-section are studied. A qualitative triangulation of the surface of a cylindrical tube, a smoothed and experimental channel of a variable cross section is constructed. The problem is solved numerically using boundary element method in several modifications for a periodic and non-periodic flows. The obtained numerical results are compared with the analytical solution for the Poiseuille flow.


Author(s):  
Matthew J. Genge

Drawings, illustrations, and field sketches play an important role in Earth Science since they are used to record field observations, develop interpretations, and communicate results in reports and scientific publications. Drawing geology in the field furthermore facilitates observation and maximizes the value of fieldwork. Every geologist, whether a student, academic, professional, or amateur enthusiast, will benefit from the ability to draw geological features accurately. This book describes how and what to draw in geology. Essential drawing techniques, together with practical advice in creating high quality diagrams, are described the opening chapters. How to draw different types of geology, including faults, folds, metamorphic rocks, sedimentary rocks, igneous rocks, and fossils, are the subjects of separate chapters, and include descriptions of what are the important features to draw and describe. Different types of sketch, such as drawings of three-dimensional outcrops, landscapes, thin-sections, and hand-specimens of rocks, crystals, and minerals, are discussed. The methods used to create technical diagrams such as geological maps and cross-sections are also covered. Finally, modern techniques in the acquisition and recording of field data, including photogrammetry and aerial surveys, and digital methods of illustration, are the subject of the final chapter of the book. Throughout, worked examples of field sketches and illustrations are provided as well as descriptions of the common mistakes to be avoided.


IEEE Access ◽  
2021 ◽  
pp. 1-1
Author(s):  
Eustaquio Martinez-Cisneros ◽  
Luis A. Velosa-Moncada ◽  
Ernesto A. Elvira-Hernandez ◽  
Omar I. Nava-Galindo ◽  
Luz Antonio Aguilera-Cortes ◽  
...  

2021 ◽  
Vol 13 (6) ◽  
pp. 3255
Author(s):  
Aizhao Zhou ◽  
Xianwen Huang ◽  
Wei Wang ◽  
Pengming Jiang ◽  
Xinwei Li

For reducing the initial GSHP investment, the heat transfer efficiency of the borehole heat exchange (BHE) system can be enhanced to reduce the number or depth of drilling. This paper proposes a novel and simple BHE design by changing the cross-sectional shape of the U-tube to increase the heat transfer efficiency of BHEs. Specifically, in this study, we (1) verified the reliability of the three-dimensional numerical model based on the thermal response test (TRT) and (2) compared the inlet and outlet temperatures of the different U-tubes at 48 h under the premise of constant leg distance and fluid area. Referent to the circular tube, the increases in the heat exchange efficiencies of the curved oval tube, flat oval tube, semicircle tube, and sector tube were 13.0%, 19.1%, 9.4%, and 14.8%, respectively. (3) The heat flux heterogeneity of the tubes on the inlet and outlet sides of the BHE, in decreasing order, is flat oval, semicircle, curved oval, sector, and circle shapes. (4) The temperature heterogeneity of the borehole wall in the BHE in decreasing order is circle, sector, curved oval, flat oval, and semicircle shapes. (5) Under the premise of maximum leg distance, referent to the heat resistance of the tube with a circle shape at 48 h, the heat exchange efficiency of the curved oval, flat oval, semicircle, and sector tubes increased 12.6%, 17.7%, 10.3%, and 7.8%, respectively. (6) We found that the adjustments of the leg distance and the tube shape affect the heat resistance by about 25% and 12%, respectively. (7) The flat-oval-shaped tube at the maximum leg distance was found to be the best tube design for BHEs.


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