某履带式急救车水上行驶阻力仿真研究

Numerical Simulation for Steering Resistance of Some Tracked Emergency Ambulance

目的:研究某履带式急救车水上行驶阻力构成,分析各种阻力对履带式急救车行驶的影响。方法:运用计算流体动力学(CFD)方法对履带式卫生急救车的水上行驶阻力特性进行了仿真。结果:前车和后车之间区域以及后车后部形成涡旋运动,涡旋运动造成涡流损失,导致压力骤降,形成低压区,会大幅度增加黏压阻力,从而增加履带式卫生急救车在水上行驶时的阻力。前车前部方形结构和后车前部尖角结构会造成这些区域形成高压区,压力梯度较大,这是形成车体绕流阻力的重要原因。履带式卫生急救车在水上行驶过程中行驶速度较低,故形成的兴波阻力不大。结论:履带式卫生急救车各种阻力均不会对其水上行驶造成较大影响,行驶较为平稳。

Objective To study the resistance composing and analyze all kinds of resistance influences of emergency ambulance. Methods Computational fluid dynamic（CFD） technology was used to investigate the sailing resistance characte- ristic of all-terrain tracked emergency ambulance. The simulation results were validated by the experimental results based on the sailing experiment. Romilts Swirls came into being between the front vehicle and back vehicle and at stern of back vehicle. Swirls led to swirl loss and created low pressure zone, finally causing increaed viscous resistance and sailing resistance of all-terrain tracked emergency ambulance. High pressure zone was created at anterior of front vehicle with square structure and at stem of back vehicle with sharp comer structure, which were the main reason of circle resistance generation of all-terrain tracked emergency ambulance. Wave resistance was relatively small because of low sailing velocity of all-terrain tracked emergency ambulance. Conclusion The resistance of emergency ambulance doesn＇t affect emergency ambulance＇s running on water.[Chinese Medical Equipment Journal, 2013,34 （1） ： 4-7]