This paper proposes an alternating elliptical impingement chamber in the leading edge of a gas turbine to restrain the cross flow and enhance the heat transfer, and investigates the detailed flow and heat transfer characteristics. The chamber consists of straight sections and transition sections. Numerical simulations are performed by solving the three-dimensional (3D) steady Reynolds-Averaged Navier–Stokes (RANS) equations with the Shear Stress Transport (SST) k– $\omega$ turbulence model. The influences of alternating the cross section on the impingement flow and heat transfer of the chamber are studied by comparison with a smooth semi-elliptical impingement chamber at a cross-flow Velocity Ratio (VR) of 0.2 and Temperature Ratio (TR) of 1.00 in the primary study. Then, the effects of the cross-flow VR and TR are further investigated. The results reveal that, in the semi-elliptical impingement chamber, the impingement jet is deflected by the cross flow and the heat transfer performance is degraded. However, in the alternating elliptical chamber, the cross flow is transformed to a pair of longitudinal vortices, and the flow direction at the centre of the cross section is parallel to the impingement jet, thus improving the jet penetration ability and enhancing the impingement heat transfer. In addition, the heat transfer in the semi-elliptical chamber degrades rapidly away from the stagnation region, while the longitudinal vortices enhance the heat transfer further, making the heat transfer coefficient distribution more uniform. The Nusselt number decreases with increase of VR and TR for both the semi-elliptical chamber and the alternating elliptical chamber. The alternating elliptical chamber enhances the heat transfer and moves the stagnation point up for all VR and TR, and the heat transfer enhancement is more obvious at high cross-flow velocity ratio.

中文翻译：

---

不同横流条件下交替椭圆室对叶片前缘射流冲击传热的影响

本文提出了一种在燃气轮机前缘的交替椭圆冲击室，以抑制横流并增强传热，并研究了详细的流动和传热特性。腔室由直线段和过渡段组成。通过求解具有剪切应力传递 (SST) 的三维 (3D) 稳定雷诺平均纳维-斯托克斯 (RANS) 方程来执行数值模拟ķ–$\欧米茄$湍流模型。通过与光滑半椭圆冲击室在横流速度比（虚拟现实) 的 0.2 和温度比 (TR) 在主要研究中为 1.00。然后是横流的影响虚拟现实和TR被进一步调查。结果表明，在半椭圆冲击室中，冲击射流被横流偏转，传热性能下降。但在交替椭圆室中，横流转变为一对纵向涡流，截面中心的流动方向与冲击射流平行，从而提高射流穿透能力，增强冲击传热. 此外，半椭圆腔内的传热在远离停滞区的情况下迅速降低，而纵向涡流进一步增强了传热，使传热系数分布更加均匀。努塞尔数随着 的增加而减少虚拟现实和TR对于半椭圆室和交替椭圆室。交替的椭圆室增强了热传递并将驻点向上移动虚拟现实和TR，并且在高横流速比下传热增强更明显。