With the increase of the turbine inlet temperature, the thermal load of serpentine nozzles increases greatly, leading to the stiffness degradation and structure deformation. Therefore, efficient cooling technologies are required. There are adverse pressure gradients (APGs) and strong swirl characteristics in the serpentine nozzle. Therefore, the film cooling design of serpentine nozzles faces greater difficulty than that of other exhaust systems. This paper aims to obtain the flow characteristics of serpentine nozzles with film cooling and to provide theoretical support for the film cooling design of serpentine nozzles. We obtained the influence of the APG and the favorable pressure gradient (FPG) on the flow characteristics of a serpentine nozzle with film cooling via the employment of numerical methods. The results show that the APG obstructs the flow of the cooling airflow, and causes a part of the cooling airflow to decelerate, to stagnate, and eventually to flow in the reverse direction, thus forming a recirculation zone. The counter rotating vortex pair (CRVP) induces the anti-counter rotating vortex pair (ACRVP) near the boundary layer of the wall, and the ACRVP develops rapidly in the recirculation zone. With the development of the ACRVP, the CRVP leaves the wall and gradually dissipates. As the blowing ratio increases, the recirculation zone moves downstream, and the recirculation zone first expands and then shrinks, such that the location where the ACRVP develops also moves downstream. There is no recirculation zone under the influence of the FPG, and the CRVP occupies the core of the cooling airflow along the flow direction.

随着涡轮进口温度的升高，蛇形喷嘴的热负荷大大增加，导致刚度退化和结构变形。因此，需要高效的冷却技术。蛇形喷嘴中存在逆压梯度 (APG) 和强涡流特性。因此，蛇形喷管的气膜冷却设计比其他排气系统面临更大的困难。本文旨在获得气膜冷却蛇形喷嘴的流动特性，为蛇形喷嘴的气膜冷却设计提供理论支持。我们通过采用数值方法获得了 APG 和有利压力梯度 (FPG) 对带薄膜冷却的蛇形喷嘴流动特性的影响。结果表明，APG阻碍了冷却气流的流动，使一部分冷却气流减速、停滞，最终逆向流动，形成回流区。反向旋转涡对（CRVP )在壁面边界层附近诱发反逆旋转涡对( ACRVP )， ACRVP在回流区迅速发展。随着ACRVP的发展，CRVP离开墙壁并逐渐消散。随着喷吹比的增加，回流区向下游移动，回流区先扩大后收缩，使得ACRVP发展的位置也向下游移动。FPG影响下无回流区，CRVP沿流动方向占据冷却气流核心。