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为揭示转子叶片径向受限的“冲击-气膜出流”冷却结构流动换热规律,以某型双层壁叶片肋化分割形成的冷却单元为研究对象,通过数值模拟的方式,对冲击雷诺数Rej,旋转数Ro,无因次温比(Tw-Tf)/Tw等参数变化下流场和换热特性变化规律展开研究。结果表明:在哥氏力和离心力作用下,受限空间内存在射流偏转、径向二次流动以及二次冲击等现象;流动的径向受限可抑制射流偏转,强化冲击换热;相同的旋转数Ro下,逆转向冲击(叶背区)换热努赛尔数Nu比顺转向冲击(叶盆区)高8%。在研究的参数范围内,数值模拟和试验结果说明径向受限周向出流结构能有效的抑制旋转对换热的削弱。
In order to reveal the regularity of flow and heat transfer of the radial “restricted” impact-membrane "cooling structure of the rotor blade, a cooling unit formed by a certain type of double-walled blade was divided into several sections. By means of numerical simulation, The variation of flow field and heat transfer characteristics under the Reynolds number Rej, rotation number Ro, Tw-Tf / Tw and other parameters were studied. The results show that under the Coriolis force and centrifugal force, jet deflections, radial secondary flows and secondary shocks exist in the confined space. Radial confinement of the flow can restrain the jet deflection and enhance the impact heat transfer. The same At the number of rotations Ro, the Nusselt number Nu for heat transfer in the reverse impact (leaf back region) is 8% higher than that in the forward impact (leaf basin). Numerical simulation and experimental results show that the radially confined circumferential outflow structure can effectively restrain the weakening of the heat transfer in the rotating range.