涡轮低压导向器优化前后气动性能对比实验研究

Comparison of Turbine Low Pressure Guide Vane before and After Optimization

采用实验方法对某型弹用涡扇发动机涡轮低压导向器原型和改型进行了详细的低速风洞实验。改型在原型基础上增加了多种优化措施。针对低压导向器进口前的中间机匣过渡段具有较大子午扩张角的结构特点,改型采用了等速度梯度过渡曲线来改善机匣段的扩压流动。为了减少导向器叶栅内能量损失的增长,改型采用了正弯叶片、后部加载叶型以及其它综合措施。实验结果表明,改型低压导向器的气动性能显著提高,出口总压损失比原型相对减少14.7%,出口气流角沿叶高分布较原型均匀。几种减少损失的方法得到了合理的匹配。

Detailed flow field measurements were conducted in a low speed wind tunnel for both original and modified LGV's which are used in turbofan engines. Optimizing approaches are introduced for the modified design. Considering the geometry feature of the transit duct before the LGV inlet that it has a large meridional diffusing angle, equal velocity gradient profile is employed in the modified design in order to control the separate flow. Moreover, the modified design employs positively curved blade, rear-loaded airfoil and other approaches to reduce the increase in energy loss. The results show that the aerodynamic performance of the modified design is improved significantly: the total pressure loss decreased by 14-7%; the exit flow angle along the blade height becomes more uniform than that of the original design. The methods which can reduce energy loss are reasonably conjugated.