摘要
在现代燃气轮机的设计中,气膜冷却技术有效地阻止了高温燃气来流对于叶片的损伤。采用数值模拟的方法,针对圆形气膜孔近壁面区域的流场进行分析。运用大涡模拟(LES)湍流模型,分别在吹风比为0.5和1.0的情况下,分析了叶片气膜孔出口的近壁面部分流动状态和壁面气膜冷却效率分布情况,并与实验结果进行对比。从结果中可以看出,数值模拟精确地捕捉到气膜冷却涡结构变化对气膜冷却的影响。在射流与主流气体的混合过程中,大涡模拟更清晰地显示出上升涡结构对于冷却效率的微小变化的作用以及涡结构分离所产生的影响。
In the design of modern gas turbine blades, the technical of film cooling is an effective way to prevent the damage from high temperature gas windward. This paper investigates the flow field and thermal characteristics in the near-field region of film cooling jets through numerical simulation using large eddy simulation （LES） model. Detailed simulations of flow and thermal fields of a single-row of film cooling round holes with 90 deg injection on a flat plate are obtained for low blowing ratio（M = 0.5 ） and high （M = 1.0） blowing ratio. The near-field region of film cooling jet and film cooling effectiveness obtained by this model are compared with available experimental data. The results of numerical simulation are presented to elucidate the formation, convection and breakdown of flow structures associated with the highly anisotropic flow. It is shown that LES model accurately predicts the result of the film cooling effectiveness dominated by the vortices. Especially in the mixing of jet in cross flow, the detail evolution of the upright vortices and the detached vortices effecting on the film cooling are discussed.
出处
《汽轮机技术》
北大核心
2016年第1期29-32,共4页
Turbine Technology
基金
国家海洋公益性行业专项资金项目(编号:201005002)
