叶片前缘气膜冷却数值模拟

为了研究叶片前缘区域的换热特性,采用非结构化网格和realizable紊流模型,求解三维N-S方程,对前缘带有一排冷气孔的涡轮叶片进行了换热特性的数值模拟.分析了不同动量比,湍流度,孔间距及径向角下冷气射流的运动规律,换热分布以及冷效分布特点.结果表明,当动量比Ⅰ大于1时,在相同孔型下,动量比越高,冷效越大.在相同动量比下,孔间距越小,冷效越大.但动量比,孔间距及径向角对换热系数影响不大.当湍流度增加时,换热系数增加而冷效降低.沿展向,气膜孔中心区域冷效较高,两孔之间区域较低;而换热系数则相反,气膜孔中心区域换热系数较小,两孔之间区域较大.

Numerical Simulation of Film Cooling on the Leading Edge of turbine blade

Detailed numerical simulations on the three-dimensional N-S equation solver turbulent flow and heat transfer were carried out with one row injection on the leading edge.The characteristics of the flow and temperature fields,including the coolafit trajectory,the heat transfer and the complicated distribution of adiabatic effectiveness in the region of leading edge are all expounded under different momentum ratios,injection angles and hole pitch.The results show that the influences of different positions of coolant holes,and the momentum ratios on the adiabatic effectiveness are obvious and complicated in the leading edge.