1+3/2级对转涡轮气动性能试验研究

无导叶对转涡轮是高性能发动机的关键技术之一。本文采用试验方法对1+ 3/2级对转涡轮进行了气动性能研究。本试验分为3个阶段，第1阶段为单独高压涡轮（HPT）试验，第2阶段为加大HPT和低压涡轮（LPT）间轴向间距联合试验，第3阶段为HPT和LPT间正常轴向间距联合试验。在正常轴向间距HPT和LPT试验中，LPT状态的确定通过利用单独HPT试验获得的效率与压比特性反推获得。试验表明，HPT喉道面积减小，而LPT喉道面积增大，这导致在总膨胀比一定情况下，HPT膨胀比增大，LPT膨胀比下降，同时LPT的存在对HPT特性影响不大。在总膨胀比分配中，HPT膨胀比变化很小，而LPT膨胀比变化范围较宽。涡轮级总效率由HPT决定，LPT轮一般相对较低，加大HPT和LPT间轴向间距对LPT性能影响很小。

Experimental research of 1 +3/2 contra-rotating turbine aerodynamic performance

Vaneless contra-rotating turbine is one of the key technologies of the high performance engine. Experimental research was conducted to investigate aerodynamic performance of 1+3/2 contra-rotating turbine. The experiment was tested over three phases:first the alone high pressure turbine(HPT) experiment, second the HPT and low pressure turbine(LPT) with axial gap enlarging between them, and finally HPT and LPT with normal axial gap. In the normal gap experiment, the condition of LPT was confirmed by HPT performance curve by converse calculation. Research shows that LPT has little effect on HPT performance; HPT throat decreases while LPT throat increases, which leads to HPT expansion ratio increasing at the constant total expansion ratio. HPT expansion ratio changes very little during the total expansion ratio varying; however LPT expansion ratio changes greatly. The turbine efficiency is mainly determined by HPT, and the LPT is generally relative low. Enlarging axial gap between HPT and LPT has little influence on LPT performance.