为了提高燃气轮机动叶的气膜冷却效果,采用Realizablek-ε湍流模型,并结合Simple算法和有限体积法对三维定常不可压缩N-S方程进行离散,在不同吹风比和主流湍流度条件下,分析了某重型燃气轮机孔间距对动叶气膜冷却效率的影响.结果表明:在一定条件下,随着孔间距的增大,冷却气体覆盖程度变差,冷却效率下降;受到叶片前缘孔排冷气的动量叠加,叶片后缘孔排气膜冷却效率明显高于前缘孔排气膜冷却效率;相同孔间距下,随着吹风比的增大,叶片综合冷却效率呈现升高的趋势;在其他条件一定的情况下,吹风比M=1.4时,主流湍流度越大,气膜冷却效率越低,但影响较小.
To improve the cooling effectiveness of a gas turbine moving blade,three-dimensional constant incompressible N-S equations were dispersed based on Realizable k-ε turbulence model combined with Simple algorithm and finite volume method,so as to analyze the influence of hole spacing on the film cooling effectiveness of the moving blade in a heavy-duty gas turbine under different blowing ratios and mainstream turbulence conditions.Results show that under certain conditions,with the rise of hole spacing,the cooling air coverage reduces and the cooling efficiency lowers.The cooling effectiveness of the trailing edge is obviously higher than that of the leading edge due to the superposition effect from the leading edge.Under same hole spacing,the comprehensive cooling effectiveness of the moving blade increases with the rise of blowing ratio.When other conditions are fixed,in case of M=1.4,the greater the mainstream turbulence is,the lower the film cooling efficiency will be,however,the influence is relatively small.