某型直升机进气舱流场数值仿真

针对某型直升机在悬停状态下发动机所出现的喘振问题,提出了进气舱的7种结构改进方案,用数值方法研究了在进气舱内增设圆弧形导流板和下移进气口下唇缘时进气舱/进气道的流场分布.仿真区域离散采用了非结构化网格和网格自适应技术.结果表明,各方案进气舱/进气道在悬停状态下均存在不同程度的气流分离;在舱内侧增设导流板和改变进气口下唇缘尺寸可以改善气流品质.试飞试验表明,增设导流板并下移进气口下唇缘可以防止发动机在悬停状态下发生喘振,保证发动机性能.

Numerical simulation of airflow field of helicopter inlet cabin

Seven improvement packages for inlet cabin were developed to resolve the problem of engine surge in a helicopter under the hovering flight conditions. Airflow field distribution of inlet cabin/intake was numerically studied for setting circular arc baffle in the inlet cabin and moving downward the lower lip of air inlet.And,unstructured grid and grid self-adaptive technology were applied for regional simulation discretion.The results indicate that local flow separation exists in the inlet cabin/intake for each package under the hovering flight conditions,and the airflow quality can be improved by setting baffle inside the cabin and changing the size of the lower lip of air inlet.Flight-test results show that the engine surge under hovering flight conditions can be prevented to ensure engine performance by using the above-specified methods.