格子阵列引发纵向涡对多孔射流冲击冷却的影响

The Influence of Longitudinal Vortexes Induced by Latticework Array upon Multi-Jet Impingement Cooling

为提升船用燃气轮机涡轮叶片的内部冷却性能,对双层壁构型中的内腔进行格子阵列化设计,采用三维数值模拟方法对比分析格子阵列结构和光滑结构的流动传热特性。结果表明,格子阵列中形成的有序大尺度强制纵向涡,能够在大幅强化内腔传热的同时,使外腔射流冲击获得更高的初始动量,克服横流影响,强化靶面传热,形成内外协同的强化传热能力。格子阵列能有效改善射流冲击的孔间分配,从而提高靶面传热的展向均匀性。研究结果对涡轮叶片双层冷却构型的优化设计有一定的指导意义。

A latticework array is designed for the internal channel of double-wall cooling configuration to improve the cooling performance of marine gas turbine blade.Three-dimensional numerical simulation is carried out to accomplish a comparative analysis on the flow and heat transfer characteristics of latticework and smooth structures.The results indicate that the organized large-scale forced longitudinal vortexes induced by latticework array not only can greatly enhance heat transfer in the internal channel,but also can impose higher initial momentum to the jet impingement in the external channel,thus to overcome the crossflow effect and augment heat transfer on the target plate.Therefore,a synergistic internal-and-external heat transfer enhancement capability can be formed.Latticework array can also effectively rearrange the distribution of multi-jet impingement flow,and thus improves the transvers uniformity of heat transfer on the target plate.The research results have certain guiding significance for the optimization design of double-layer cooling configuration of turbine blade.