考虑端部槽缝射流压力扰动的造型端壁研究

The Study of Contoured Endwall with Considering the Pressure Disturbance of Purge Flow

以某典型高压涡轮平面叶栅为研究对象,分别研究了槽缝射流导致的端壁静压变化对3种造型幅值下的非轴对称端壁造型气动、冷却及换热特性变化规律。结果表明:MFR=0.75%时,随造型幅值增加,总压损失逐渐减小,叶栅总压损失系数最大可降低2.208%;端壁造型可显著增加高冷效区面积,但叶片前缘至55%Cax范围内的横向平均气膜有效度降低;对于传热特性而言,端壁造型可以削弱前缘及通道中后部的换热强度,造型幅值越大,削弱效果越明显,面平均换热系数最大降低7.11%;基于带有槽缝射流的端壁静压分布进行造型更有利于提高端壁的冷却特性,降低换热强度。

Taking a typical high pressure turbine plane cascade as the research object,the changes of endwall static pressure caused by purge flow on the aerodynamic,cooling and heat transfer characteristics of non-axisymmetrical endwall under three modeling amplitudes are studied.Results indicated that when MFR=0.75%,the total pressure loss reduces with increasing modeling amplitude and drops by 2.208%in cascade total pressure loss coefficient.The region of the high cooling performance zone may be greatly increased by contoured endwall,however the transverse average film effectiveness declines from the leading edge to 55%Cax.Regarding the features of heat transfer,contoured endwall can reduce the heat transfer strength of the leading edge and rear part of endwall.The maximum surface average heat transfer coefficient is decreased by 7.11%,and the weakening impact becomes more apparent as the modeling amplitude increases.It is easier to improve the cooling characteristics and reduce the level of heat transfer by modeling based on the endwall static pressure distribution with purge flow.