风扇/增压级带间隙三维粘性流场数值模拟

使用三维数值模拟软件NUMECA(Numerical Mechanics Application)对双涵道风扇/增压级带转子叶尖间隙的粘性流场进行了三维定常流动数值模拟,获得了其设计转速下的流场特性.结果显示,随着外涵背压的升高,风扇顶部激波后阻塞区周向和轴向尺寸增大,激波变形加剧,继续提高外涵压比,则外涵效率和进出口流量下降.内涵背压的升高,使内涵各转子叶片顶部的泄漏流动影响范围向上游扩散.内涵背压过高,效率和进出口流量同样会有下降的趋势.同时通过和实验结果的比较表明,数值模拟软件模拟的风扇/增压级的三维定常粘性流场能够较真实的反映出转子叶尖间隙泄漏流场的结构特征,以及间隙对流场参数的影响.

Numerical simulation of three dimension viscous flow of fan/compressor with tip clearance

A three dimension numerical simulation software named NUMECA(numerical mechanics application) was used to calculate the tip clearance flow of fan/compressor.The flow field performance under design speed condition was obtained.The results show that when back pressure of by-pass duct increases,the intensive blockage area moves upstream and towards the fan pressure surface,and twist of shock become more obvious.The efficiency and the mass flow of the by-pass duct decrease if the back pressure of the by-pass duct increases unceasingly.At core duct,the area influenced by tip clearance leakage flow spreads to upstream with the increase of back pressure.In the same way,the efficiency and the mass flow of the core duct decrease if the back pressure of core duct is too great. The comparison between the results and the experiments shows that the numerical simulation results of three dimension viscous flow of fan compressor with tip clearance could actually reflect the influences of leakage flows on the flow structure and parameters.