The paper studies on relations between railway rolling stock and peripheral interfaces in Japanese railways.It covers the relations between wheel and rail,the relations between pantograph and catenary,the air dynamics...The paper studies on relations between railway rolling stock and peripheral interfaces in Japanese railways.It covers the relations between wheel and rail,the relations between pantograph and catenary,the air dynamics,track circuit and noise,etc.In the study on relations between wheel and rail,the adhesive property between wheel and rail,the lubrication of wheel and rail and wear reduction between wteel flange and inner rail corner were analyzed.In the study on relations between pantograph and catenary,the author focused on the contact status between the pantograph and catenary,e.g.,how to minimize the variation of the contact force,causes of the variation and the protection measures.In dynamics study,Increase of rolling stock shock in tunnels and shock absorption measures are analyzed.In track circuit study,reduction of wheel/rail contact resistance is analyzed.In noise study,causes of rolling noise and structural noise as well as the numerical value module are analyzed.展开更多
Mathematical models of propellers were created that investigate the influence of periodic boundary conditions on predictions of a propeller's performance.Thrust and torque coefficients corresponding to different a...Mathematical models of propellers were created that investigate the influence of periodic boundary conditions on predictions of a propeller's performance.Thrust and torque coefficients corresponding to different advance coefficients of DTMB 4119, 4382, and 4384 propellers were calculated.The pressure coefficient distribution of the DTMB 4119 propeller at different sections was also physically tested.Comparisons indicated good agreement between the results of experiments and the simulation.It showed that the periodic boundary condition can be used to rationally predict the open water performance of a propeller.By analyzing the three established modes for the computation, it was shown that using the spline curve method to divide the grids can meet the calculation's demands for precision better than using the rake cutting method.展开更多
In two dimensions, we study the compressible hydrodynamic flow of liquid crystals with periodic boundary conditions. As shown by Ding et al. （2013）, when the parameter λ→∞ oo, the solutions to the compressible li...In two dimensions, we study the compressible hydrodynamic flow of liquid crystals with periodic boundary conditions. As shown by Ding et al. （2013）, when the parameter λ→∞ oo, the solutions to the compressible liquid crystal system approximate that of the incompressible one. Furthermore, Ding et al. （2013） proved that the regular incompressible limit solution is global in time with small enough initial data. In this paper, we show that the solution to the compressible liquid crystal flow also exists for all time, provided that is sufficiently large and the initial data are almost incompressible.展开更多
文摘The paper studies on relations between railway rolling stock and peripheral interfaces in Japanese railways.It covers the relations between wheel and rail,the relations between pantograph and catenary,the air dynamics,track circuit and noise,etc.In the study on relations between wheel and rail,the adhesive property between wheel and rail,the lubrication of wheel and rail and wear reduction between wteel flange and inner rail corner were analyzed.In the study on relations between pantograph and catenary,the author focused on the contact status between the pantograph and catenary,e.g.,how to minimize the variation of the contact force,causes of the variation and the protection measures.In dynamics study,Increase of rolling stock shock in tunnels and shock absorption measures are analyzed.In track circuit study,reduction of wheel/rail contact resistance is analyzed.In noise study,causes of rolling noise and structural noise as well as the numerical value module are analyzed.
基金Supported by the National Natural Science Foundation of China under Grant No.10702016
文摘Mathematical models of propellers were created that investigate the influence of periodic boundary conditions on predictions of a propeller's performance.Thrust and torque coefficients corresponding to different advance coefficients of DTMB 4119, 4382, and 4384 propellers were calculated.The pressure coefficient distribution of the DTMB 4119 propeller at different sections was also physically tested.Comparisons indicated good agreement between the results of experiments and the simulation.It showed that the periodic boundary condition can be used to rationally predict the open water performance of a propeller.By analyzing the three established modes for the computation, it was shown that using the spline curve method to divide the grids can meet the calculation's demands for precision better than using the rake cutting method.
基金supported by National Basic Research Program of China(973 Program)(Grant No.2011CB808002)National Natural Science Foundation of China(Grant Nos.11001085,11071086 and 11128102)+2 种基金the University Special Research Foundation for PhD Program(Grant No.20104407110002)the PhD Programs Foundation of Ministry of Education of China(Grant No.20100172120026)the Fundamental Research Funds for the Central Universities(Grant No.2012ZZ0075)
文摘In two dimensions, we study the compressible hydrodynamic flow of liquid crystals with periodic boundary conditions. As shown by Ding et al. （2013）, when the parameter λ→∞ oo, the solutions to the compressible liquid crystal system approximate that of the incompressible one. Furthermore, Ding et al. （2013） proved that the regular incompressible limit solution is global in time with small enough initial data. In this paper, we show that the solution to the compressible liquid crystal flow also exists for all time, provided that is sufficiently large and the initial data are almost incompressible.
