双级高压涡轮气动性能试验状态模化方法

针对双级高压气冷涡轮的低温试验状态模化方法,对以空气为工质、基于不同相似准则数的试验模化状态的流场相似性进行数值仿真。结果表明：对于有冷气试验模化方法,采用出口马赫数与设计状态一致的模化方法可获得相似性较好的试验状态流场,此时反力度、载荷系数、马赫数均能保证良好的相似性,主要相似准则数偏差不超过5%;对于无冷气试验模化方法,保持涡轮几何不变并增大膨胀比使得等熵速比与设计状态的一致,或通过改变叶片数保证各排出口马赫数与设计状态的一致,均能显著改善无冷气模化状态与设计状态的流场相似性。其中前者反力度相似性接近98%,而后者载荷系数和马赫数的相似性达到了同样水平,但破坏了模型的几何相似。

Model Testing State Determination for a Two-Stage High Pressure Turbine Aerodynamic Performance Test

Aiming at the model testing of an air-cooled two-stage high pressure turbine at low-temperature states, numerical simulationswere conducted on the flow field similarity of the model testing state withair as working fluid and based on different similarity criterion num-bers. The results show that among the test modeling methods with cooling air, a modeling method with the outlet Mach number consistent withthe design state can obtain a flow field with good similarity, whilst the reaction, loading coefficient, and Mach number all exhibit good similari-ty, the deviation of the main similarity criterion numbers is less than 5%; among the test modeling methods without cooling air, keeping the tur-bine geometry unchanged and increasing the expansion ratio to make the isentropic-speed-ratio consistent with the design state, or changingthe number of blades to ensure the outlet Mach number of each blade row consistent with the design state can significantly improve the similar-ity of the flow field between the uncooled mode and the design state. The similarity of reaction of the former is close to 98%, while the similari-ty of the loading coefficient and Mach number of the latter reaches the same level, but it destroys the geometric similarity of the model.