叶片反扭对跨声速大涵道比风扇性能的影响

使用基于流固耦合算法的叶片反扭程序,考虑了非定常气动力对叶片变形的非线性作用,研究了叶片反扭对跨声速大涵道比风扇性能的影响.以冷态叶型为起点,先计算离心力作用下的叶片变形,在此基础上使用流固耦合程序获得非定常气动力作用下的变形.考察了3个转速下叶片的动态变形对大涵道比风扇气动性能的影响.结果表明:在跨声速工况下,叶片表面激波位置的变化对叶片反扭角有很大作用,在考察的转速范围内,堵塞点使用设计叶型计算的流量大于动态叶型下的流量,数值达7%,将导致发动机起飞推力小于预测值.结果表明在大涵道比风扇设计阶段,预测气动性能使用准确叶型的重要性. 

Influence of blade untwist on transonic high bypass ratio fan performance

Influence of blade untwist on transonic high bypass ratio fan performance were studied using the software based on the fluid-solid coupling algorithm, considering the nonlinear effects of unsteady aerodynamic force on the blade deformation. Firstly, the deformation induced by centrifugal force was calculated starting from the cold blade shape, and then the deformation induced by unsteady aerodynamic force was obtained using the fluid-solid coupling software. The effect of the dynamic blade deformation on aerodynamic performance of the high bypass ratio fan was investigated at three rotation speeds. Results show that changes of the shock position on the blade surface have significant influence on the blade untwist angle under the transonic conditions. In the rotation speed range concerned, the calculated mass flow rate by the designed blade shape is greater than that by the dynamic one up to 7%, which causes the engine takeoff thrust less than the predicted value. The results also indicate that the accurate blade shape is important for predicting aerodynamic performance during the design stage.