环量控制技术研究

未来军/民运输机的高性能要求促使近年来环量控制技术正成为研究的新热点。本文简单介绍了环量控制研究的进展;深入讨论了包括二维环量控制翼型标模和CCA/OTW(Circulation Control Airfoil/Over the Wing)实验、半模型子系统实验和三维翼身融合体全机实验等可供CFD验证用的NASA实验研究。在2个尺寸相近的风洞中对同一二维标模的实验结果表明,源于切向吹气的最大升力系数C_Lmax在中等缝道出口高度时可达8~9。数据对比表明此实验结果可供计算流体力学(CFD)验证用。二维CCA/OTW实验表明,发动机位置前移可大幅增大失速迎角和C_Lmax;CCA后缘吹气噪声的低频部分强度与速度的8次方成正比,高频部分与速度的6次方成正比。半模型子系统的FACT-MAC跨声速实验不仅可研究高雷诺数效应,且可提供2种飞行状态的数据。初步结果表明,与无射流的低速数据相比,在α=25°时C_L增大约33%,跨声速时在非设计状态下射流可有效地使激波诱导的分离再附,在保持原有强度下激波位置可后推5%的弦长。三维全机CCW/OTW的实验数据尚在整理分析中,但初步结果已表明,应用前缘吹气可将失速迎角增大至25°,C_Lmax增大至6,正确安排OTW位置可增大升力线斜率等。

Study of the circulation control technology

The circulation control technology is being a new reseach highlight recently, due to the high performance needs of the fufure military/commercial transports. The research progress of the circulation control is introduced briefly and the NASA experimental research plan, including 2D CC airfoil benchmark and CCA/OTW(circulation control airfoil/over the wing)experiments, half-model subsystem experiments, and 3D hybrid wing body aircraft experiments, intended for CFD code validation is discussed in detail in the present paper. The experimental data of the same model in two similar sized wind tunnels shows that when the slot exit height is moderate C_Lmax can be reach 8-9 due to the tangential blowing. Comparison of the 2 tunnels' data indicates that the data can be used for CFD validation. 2D CCA/OTW experiments show that both stall angle of attack and C_Lmax can be increased largely by the position forward movement of the engine. The lower frequency intensity of the trailing blowing noise is proportional to the velocity's 8th power and the higher frequency's is 6th. Results of the half model subsystem FACT-MAC transonic experiments can be used not only to study the effect of high Reynolds number, but also to provide the results of two flight regimes. The preliminary results indicate that comparing with no blowing the increase of C_L is about 33% at α=25° at low speed, and the separation induced by shock wave can be effectively reattached and the shock wave's position is moved aft 5% chord while keeping its strength in off-design condition at transonic speed. Being analysed and compared now, the results of 3D large scale full span CCW/OTW aircraft tests will be presented in the upcoming NASA TM. The published data illustrates that with leading edge blowing the wing stall angle of attack can be greater than 25ånd C_Lmax can be increased to over 6. And the lift curve slope is increased with the application of OTW.