Two flow cases for scaled high speed train models with different length are numerically analyzed in the framework of the improved delayed detachededdy simulation model.Specific attention is paid to the shear flows and related mechanisms in the near turbulent wake created by these moving models.In particular,a comparative analysis is made on the distributions of turbulent kinetic energy(TKE)and turbulence production(TP)in planes perpendicular to the streamwise direction.The numerical results suggest that,in the wake region very close to the tail,significant TKE and TP can be ascribed to the dynamic interaction between powerful eddies and strong shear,which explain why these quantities are sensitive to the shear strength.The shear flows are essentially governed by the boundary layers developing along the streamwise direction on the train surfaces,especially from the under-body region and the side walls.For other positions located in the downstream direction away from the tail,the interaction of vortices with the non-slip ground serves as a mechanism to promote transfer of energy from weak eddies to turbulence through the shear present in planes parallel to the ground.
展开▼
机译:名称:激光绑带蝙蝠速度训练器。描述:用臀部而不是上身(肩膀和手臂)摆动,可以提高击球速度。使用我们的Laser Strap Bat Speed Trainer时,如果您的上半身摇摆,则会导致地面球变弱,弹出或摇摆而丢失。激光绑带蝙蝠速度训练器可以将肘部紧贴身体,帮助您的核心保持与挥杆的连接。改善双手的上挥杆动作对于提高力量至关重要。