The sealing flow will inevitably affect the cooling airflow quality in a second air system of an aero-engine. In this study, theoretical derivation and numerical simulation were conducted to establish a modified mixing model that considers both the torque and the source of the mixing flow. Then, the effect of the sealing flow can be evaluated using the modified mixing model. The results demonstrate that the effects of the sealing outflow on the flow and temperature characteristics of the pre-swirl system are weak when the air supply mass flow rate and pressure are fixed. However, the effects of the sealing inflow are significant. When the inner sealing inflow mass flow rate is increased from 0 to 20%, the temperature drop effectiveness is decreased by 31.3%. The temperature drop effectiveness is decreased by 29.2% as the inner sealing inflow temperature rises by 37 K. Then, the temperature drop effectiveness is increased by 15.6% as the inner sealing inflow swirl ratio is increased from 0 to 0.8. The results of the modified mixing model are in satisfactory agreement with the numerical results, which show a maximum temperature drop deviation of 7.22%. Compared with the previous method, the prediction accuracy of the pre-swirl cavity temperature drop can be increased by 22.28%.

密封流将不可避免地影响航空发动机的第二空气系统中的冷却气流质量。在这项研究中，进行了理论推导和数值模拟，以建立同时考虑扭矩和混合流源的改进混合模型。然后，可以使用修改后的混合模型评估密封流的效果。结果表明，当空气供应质量流量和压力固定时，密封流出对预旋流系统的流量和温度特性的影响微弱。然而，密封流入的影响是显着的。当内部密封流入质量流量从0增加到20％时，降温效果降低31.3％。温度下降效率降低29。当内部密封流入温度升高37 K时为2％。然后，随着内部密封流入涡流比从0增加到0.8，降温效率提高了15.6％。改进的混合模型的结果与数值结果令人满意，其最大温度下降偏差为7.22％。与以前的方法相比，预旋腔温度下降的预测精度可以提高22.28％。