The computational fluid dynamics （CFD） method is used to investigate the aerodynamic characteristics of the seat/occupant with windblast protection devices. The upwind Osher scheme is used for the spatial discretisa...The computational fluid dynamics （CFD） method is used to investigate the aerodynamic characteristics of the seat/occupant with windblast protection devices. The upwind Osher scheme is used for the spatial discretisation. The detached-eddy simulation （DES） based on the Spalart-Allmaras one-equation turbulence model is ap- plied to the detached viscous flow simulation behind the seat/occupant, with Mach numbers 0.6 and 1.2 at attack angles between --10 and 30°, and at two sideslip angles of 0 and 15°, respectively. The aerodynamic characteristics of seat/occupants with and without windblast protection devices are calculated in cases of the freestream Mach numbers 0. 8 and 1.6, attack angles from 5 to 30°, and three sideslip angles of 0, --20 and --50°, respectively. Results show that simulation results agree well with experimental data. And the occupant is efficiently protected by windblast protection devices.展开更多
Mei symmetry and Mei conserved quantity for a non-holonomic system of non-Chetaev's type with unilateralconstraints in the Nielsen style are studied.The differential equations of motion for the system above are es...Mei symmetry and Mei conserved quantity for a non-holonomic system of non-Chetaev's type with unilateralconstraints in the Nielsen style are studied.The differential equations of motion for the system above are established.The definition and the criteria of Mei symmetry,conditions,and expressions of Mei conserved quantity deduced directlyfrom the Mei symmetry are given.An example is given to illustrate the application of the results.展开更多
基金Supported by the Aeronautical Science Foundation of China(2008ZC52039)~~
文摘The computational fluid dynamics （CFD） method is used to investigate the aerodynamic characteristics of the seat/occupant with windblast protection devices. The upwind Osher scheme is used for the spatial discretisation. The detached-eddy simulation （DES） based on the Spalart-Allmaras one-equation turbulence model is ap- plied to the detached viscous flow simulation behind the seat/occupant, with Mach numbers 0.6 and 1.2 at attack angles between --10 and 30°, and at two sideslip angles of 0 and 15°, respectively. The aerodynamic characteristics of seat/occupants with and without windblast protection devices are calculated in cases of the freestream Mach numbers 0. 8 and 1.6, attack angles from 5 to 30°, and three sideslip angles of 0, --20 and --50°, respectively. Results show that simulation results agree well with experimental data. And the occupant is efficiently protected by windblast protection devices.
基金Supported by the National Natural Science Foundation of China under Grant No.10572021Preparatory Research Foundation of Jiangnan under Grant No.2008LYY011
文摘Mei symmetry and Mei conserved quantity for a non-holonomic system of non-Chetaev's type with unilateralconstraints in the Nielsen style are studied.The differential equations of motion for the system above are established.The definition and the criteria of Mei symmetry,conditions,and expressions of Mei conserved quantity deduced directlyfrom the Mei symmetry are given.An example is given to illustrate the application of the results.
