摘要
采用Realizable k-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,对某重型燃气轮机透平第一级动叶在不同吹风比和主流湍流度条件下的气膜冷却效率进行了数值模拟。结果表明:气膜冷却能够有效地降低叶片表面的温度,但叶片前缘吹风比的改变对冷却效果的影响不是很大,在前缘滞止线两侧仍然存在较大的高温区;在压力面侧和吸力面侧,随着吹风比的增大,沿叶片展向平均冷却效率分布都得到了提高;低吹风比时,吸力面靠前缘区域孔排中的冷却孔保持单孔冷却特点,孔间区域冷却效果较差;主流湍流度对气膜冷却效果产生了明显的影响,但影响趋势因不同吹风比而各不相同,其对冷却射流的影响主要集中在气膜孔下游扩散上。
Based on Simple algorithm and the finite volume method for three-dimensional steady incompressible N-S equations were discrete, the realizable k-ε turbulence model was applied to simulate, the film cooling efficiency of the first step of turbine moving blade in a heavy duty gas turbine, under the condition of different blowing ratio and the mainstream turbulence degrees, is simulated. The result of numerical simulation shows that film cooling can be a effective way to reduce the surface temperature of the blade, but the influence of blowing ratio change on cooling performance, in the blade leading edge, is not very big, as a large area with high temperature on both sides of stagnation line of the blade leading edge is still exist. Both in the pressure side and suction side, with the increasing of blowing ratio, cooling efficiency distribution along the blade show to have improved. Under the condition of low blowing ratio, cooling holes in the leading edge rows of suction side keep the cooling characteristics of single hole, the cooling effect of the area between holes is relatively poor. Turbulence degrees of mainstream has a significant effect on the effectiveness of film cooling, but the impact tendency varies with different blowing ratio, and the impact on the cooling jet mainly spread in the downstream of the film hole.
出处
《燃气轮机技术》
2016年第4期37-43,共7页
Gas Turbine Technology
基金
中国南方电网有限责任公司科技计划项目
关键词
重型燃气轮机
气膜冷却
吹风比
数值模拟
heavy-duty gas turbine
film cooling
blowing ratio
numerical simulation
