一种腹下S弯进气道低速大攻角下气动特性实验

对一种腹下S弯进气道进行了实验研究,得到了低速大攻角下的气动特性,结果表明:随出口马赫数的增加,腹下S弯进气道出口截面的总压恢复系数不断下降,稳态周向畸变指数、紊流度和综合畸变指数均上升;出口马赫数为0.45时,进气道出口总压信号的功率谱在220 Hz处存在峰值,内通道发生了局部流动分离;与地面抽吸状态相比,该进气道在低速大攻角状态下具有较高的总压恢复系数,虽综合畸变指数也偏大,但能够满足发动机正常工作的要求.

Investigation of pneumatic characteristics for a ventral S-shaped inlet at high incidence and low speed

The pneumatic characteristics of a ventral S-shaped inlet at high incidence and low speed were investigated experimentally.The results show that when the Mach number Mae of the flow at the exit increases,the total pressure recovery decreases,and the circular steady total pressure distortion,turbulence intensity and synthesis distortion increase.When Mae is at 0.45,the total pressure recovery coefficient,circular steady total pressure distortion coefficient,turbulence intensity and synthesis distortion coefficient are 0.881,1.292%,1.513% and 2.805% respectively.At the same time,the power spectrum magnitude of the dynamic total pressure signals has a peak value at 220 Hz,which confirms that a flow separation occurs somewhere in the duct.As compared with the experimental result under ground running,the results at high incidence and low speed have a higher total pressure recovery and although the synthesis distortion is also higher,the inlet is fit enough to the engine at high incidence and low speed.