关键词: 气膜冷却, B样条曲线, 最优孔形, 优化算法, 均匀性指数

Abstract: Film cooling is an effective cooling technique for cooling turbine blades, where the shape of the outlet holes plays a critical role in enhancing cooling efficiency. Parametric modeling of the film cooling holes is performed using B-spline curves, which are defined by 11 control variables to precisely control the hole shape. This is combined with CFD numerical simulation and optimization algorithm for global optimization. The results show that the optimized hole shape exhibits inward contraction and outward expansion at the leading edge compared to the fan-shaped hole, while the trailing edge shows a concave feature similar to the heart-shaped hole. This hole shape combines the advantages of both heart-shaped and fan-shaped holes with respect to film cooling performance. It increases the cooling intensity at the center along the flow direction and improves coverage in the spanwise direction, demonstrating excellent film cooling performance. Under a blowing ratio of M=1, the film cooling efficiency of the optimal hole shape increases by 13.6% compared to the fan-shaped hole, while the uniformity index improves by 5.11%. The study proposes a B-spline parameterization and optimization algorithm for the global optimization of film cooling hole designs, providing valuable insights for the optimization design of turbine blade film cooling.

Key words: film cooling, B-spline curves, optimal hole shape, optimization algorithm, uniformity index