无导叶对转涡轮气动设计技术

采用先进的无导叶对转涡轮气动布局是提升航空发动机性能最为有效的措施之一。结合无导叶对转涡轮高压涡轮动叶进出口轴向速度变化较大等特点,采用理论分析等研究了对转涡轮基元速度三角形参数的优化选取方法,并给出了高压涡轮导叶、动叶出口气流角等变化对效率影响的详细变化关系。流量系数小、高压动叶出口气流角大以及高压动叶进出口轴向速度比大是设计满足出功比高效率对转涡轮的关键。而采用Bezier曲线造型的收敛-扩散叶型叶背曲率的控制、尾缘半径的选择、叶型出口面积与几何喉道面积之比等则是设计适合出口马赫数1.5～1.6高性能叶型的关键。

Aerodynamics design of two-stage vaneless counter-rotating turbine

Vaneless counter-rotating turbine technology is one of the most efficient ways to greatly improve aero-engines performance.As the axial velocity ratio of high-pressure turbine rotor is much larger than conventional one,the optimal selection of counter-rotating turbine velocity triangles by theoretical analysis is developed,and how effect of high-pressure turbine stator/rotor outlet flow angle on the efficiency is also figured out.The key point to design a high efficient practicable vaneless counter-rotating turbine is to select velocity triangles that charactered by low flow coefficient,high outlet flow angle and large axial velocity ratio of high-pressure turbine rotor.In blade design,the convergent-divergent throat passage is necessary.The curvature of blade suction surface and the radius of trailing edge circle should be carefully selected while generating convergent-divergent blade by Bezier.