基于动网格技术的风挡除霜新方法的数值模拟

运用CFD方法对某车型挡风玻璃除霜过程数值模拟,针对现有国标规定分区中A区除霜过慢的问题,提出了一种除霜新方法,在风口处设计能绕自身轴线回转的导流叶片,结合动网格技术,计算除霜瞬态过程.结果表明:叶片初始偏转角度为42°,A区的除霜效果最好,努赛尔数提高13.7%,270s时刻,令叶片以角速度ω=0.073 3rad/s偏转,280s时刻回转至初始位置.A区霜层除去80%面积所需时间与原模型相比缩短60s,在保证除霜完全的基础上优先除去A区霜层,实现驾驶员视野的快速清晰.

Numerical Simulation of a New Method of Windshield Defrost by Dynamic Mesh

CFD (computation fluid dynamics) was applied to simulate the vehicle windshield defrosting process. To solve the problem of slow defrosting in area A, a new method was proposed. Four defroster grilles were installed at airflow vents, which can rotate around their center axis. Combined with dynamic mesh, the transient defrosting process was calculated. The results show that, when grilles are deflected to 42 degrees, the Nusselt number of area A improves by 13.7%, making the grilles rotate at 0.0733 rad/s, and the grilles are back to the original position at 280s. Compared with the original model, the time required to defrost area A decreases by 60s. The frost covering area A is removed preferentially, which ensures that the driver's field of vision is clear and quick.