高压涡轮后腔流阻特性与瞬态换热试验研究

在航空发动机二次流系统中,涡轮盘腔的流动和换热问题伴随着复杂的几何、流动及热边界条件,为探究其流场和换热特性对发动机设计的重要作用,对一具有预旋进气孔和高、低半径出口的高压涡轮后腔内的流阻特性和转盘盘面的换热特性进行了试验研究,主要应用瞬态液晶测试技术对转盘表面的对流换热特性进行了测量。在试验中,旋转雷诺数Re_ф变化范围为8×10~5~1.0×10~6,无量纲二次流量(流量系数)C_W变化范围为5.29×10~3~1.19×10~4。试验结果表明:腔内压力及流阻特性受进气流量C_W和转盘转速Re_ф的影响;转盘表面的换热随着半径的递增以及预旋比β_p的增大而增强;出口湍流参数λ_T对换热特性影响很小。

Experimental Study of Flow Resistance and Heat Transfer in Rotor-StatorCavity for High Pressure Turbine

In secondary air system of aeroengine,flow and heat transfer problems of turbine disc system usually appear with complex geometry,flow and thermal boundary condition.The flow distribution and heat transfer characteristics are of great importance to the engine design.The experimental investigations of flow resistance and heat transfer in a rotor-stator cavity with pre-swirl inlet nozzles and two outlets at both low radius and high radius were performed.Transient thermochromic liquid Crystal (TLC) technique was employed to measure the convective heat transfer coeffcient on the test surface of the rotating disk.Experiments were carried out with rotational Reynolds number (Reφ) varying from 8×105 to 1.0×106 and dimensionless flow rate (Cw) ranging from 5.29×103 to 1.19×104.Experimental results show that the characteristics of the pressure loss coefficient between inlet and outlet depends strongly on Cw and Reφ.The heat transfer in all the conditions on the rotating disk is strengthened with the increase of the radius of disk as well as the high pre-swirl ratio (βp).The turbulence flow parameter(λr) of outlet has little influence on the heat transfer.