平板圆孔气膜冷却的热弹耦合分析

Thermo-elastic coupling analysis of round-hole flat-plate film-cooling

分析了带圆孔的平板这一基本的冷却结构的热弹耦合特性,研究了定常状态下影响热应力的因素.采用了多场耦合的计算方法预测并分析了平板圆孔气膜冷却的热应力分布,系统地分析了入射角、复合角和吹风比对热应力的影响.结果表明:平板内整体热应力远小于气膜孔周边的热应力,热应力主要集中在气膜孔前缘线和尾缘线附近,而气膜孔两侧的热应力仍保持较低的水平;施加于气膜孔的内力垂直于气膜孔的轴线.吹风比越大,气膜孔附近的温度梯度就越大,从而气膜孔的前缘线和尾缘线的热应力更加集中.入射角越小,气膜孔周边的热应力越大,而且热应力会更加集中在气膜孔出口的前缘点和入口的尾缘点上.复合角的存在有助于弱化热应力集中.

The thermo-elastic coupling property of the basic cooling configuration of flatplate with round-hole was analyzed.The factors that may influence the steady state thermal stress were studied.The thermal stress distribution of the round-hole flat-plate film-cooling was predicted and analyzed using the multi-field coupling method.The influences of the injection angle,compound angle and blowing ratio on thermal stress were systematically investigated.The results show that the overall thermal stress in the flat-plate is much lower than that of the place around the film holes,and the thermal stress only concentrates near the leading edge line and trailing edge line of the film holes,while the thermal stress remains low on the lateral sides of the film holes.The inner force imposed on the film holes is perpendicular to the axis of film hole.The higher blowing ratio means higher temperature gradient near the film holes,and more intensive thermal stress concentration near the leading edge line and tailing edge line.The smaller injection angle means higher thermal stress near the film holes,and more serious thermal stress concentration on the leading edge point of the film hole exit and the trailing edge point of the film hole inlet.The compound angle is beneficial to weakening the thermal stress concentration.