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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。
In the aero-engine secondary flow system, the flow and heat transfer problems of the turbine disk are accompanied by complex geometry, flow and thermal boundary conditions. To explore the important role of flow field and heat transfer characteristics in engine design, The characteristics of the flow resistance in the rear voids of the high-pressure turbine and the heat transfer characteristics of the turntable disk surface were studied. The transient liquid crystal test technology was used to measure the convection heat transfer characteristics of the turntable surface . In the experiment, the Reynolds number Rex is about 8 × 10 ~ 5 ~ 1.0 × 10 ~ 6, and the dimensionless secondary flow (flow coefficient) C_W is 5.29 × 10 ~ 3 ~ 1.19 × 10 ~ 4. The experimental results show that the pressure in the cavity and the flow resistance characteristic are affected by the inlet flow rate C_W and the rotational speed Re_ф of the turntable. The heat transfer on the turntable surface increases with the increase of the radius and the increase of the pre-whirl ratio β_p. The exit turbulence parameter λ_T commutates Thermal characteristics have little effect.