为了研究涡轮外环外部非定常压力波动对内部射流冲击流动换热特性的影响，采用非稳态雷诺平均的数值模拟方法获得了正弦型气膜出流压力脉动参数（波动频率和幅值）对冲击靶面换热特性的影响规律。计算表明：正弦型气膜出流压力能诱导产生相同频率不同相位的正弦型冲击入口压力和进、出口质量流量；随着气膜出口压力的波动频率增大，冲击入口压力和进、出口质量流量的波动范围不断减小，而靶面瞬时平均Nu的波动范围先减小后增大；增大出口压力振幅能增大进口压力、进出口质量流量和靶面瞬态换热的波动范围，不改变相位分布。

In order to study the effect of the unsteady pressure fluctuation outside the turbine shroud on the impingement flow heat transfer characteristics of the jet in turbine shroud,the unsteady Reynolds averaged numerical simulation method was used to obtain the influence law of the pulsation parameters (fluctuation frequency and amplitude) of the filmcooling outflow pressure with the shape of sine wave on the surfacetoflow heat transfer characteristics of the impinging target. The calculation results show that the filmcooling outflow pressure with the shape of sine wave can induce a sinusoidal impulse pressure to the inlet,thus result in the mass flow rate of the inlet and outlet sharing the same frequency but with the different phases; as the fluctuation frequency of the filmcooling outflow pressure increases,the fluctuation amplitude of inlet pressure keeps decreasing,along with the mass flow rate of the inlet and the outlet; the fluctuation range of the target surface′s instantaneous mean Nu decreases at first but increases later; the increase of outlet pressure amplitude can conduct an increase to the amplitude of inlet pressure,result in fluctuation′s growth to the mass flow rate of the inlet and the outlet,thus the instantaneous mean Nu of the target surface,without changing the phase distribution to the parameters mentioned above.

V231.1

国家自然科学基金(51936008);国家科技重大专项(2017-III-0001-0025)