跨声速风扇的弯、掠三维设计研究

Research on three-dimensional design of bowed and swept blade of transonic fan

以某小型跨声速单级轴流风扇为平台,采用数值模拟的方法,研究并探讨了弯、掠三维设计技术对具有较高负荷的跨声速轴流压气机性能改善所起到的作用和抑制流动损失增加的机理.分别探讨了在动叶上半叶高和静叶端区采用不同的弯、掠形式对风扇设计点以及等转速线上的小流量工况性能的影响.研究结果表明:动叶上半叶高采用反弯设计能够有效改变动叶端区压力梯度,减少泄漏流在出口压力面侧的堆积,增加动叶顶部的通流能力.静叶端区采用前缘反弯和尾缘正弯的复合弯、扭技术,同时实现了端区增容和控制二次流发展的目的,随着流量的减小,弯、扭设计静叶更好地控制住了端区二次流的恶化,端区损失增长明显较直叶片缓慢,风扇的稳定工作范围得到提高.

Effects of bowed and swept blade on the improvement of transonic fan performance and inhibition of the flow loss were studied by numerical simulation based on a small transonic axial fan. The swept and bowed design concept for the up half spanwise of rotor and later half spanwise of stator was discussed at the design flow condition and the less flow condition. The results show that negative bowed design for up half spanwise of rotor changes the pressure gradient near the endwall , thus , the accumulation of boundary layer near the side of pressure surface at outlet caused by the leakage flow is decreased, and the flow capacity is enhanced. The negative bowed design at leading edge and positive bowed design at trailing edge were adopted in the design of stator. The complex bowed and twisted technology can realize the increase of flow rate near the endwall and the control of the secondary flow at the same time. The bowed and twisted stator can also control the deterioration of secondary flow better with the decrease of flow rate and enlarge the range of steady operation condition obviously.