应用离散型协同射流的翼型增升减阻研究

摘要

Continuous Co⁃Flow Jet ( CCFJ) and Discrete Co⁃Flow Jet ( DCFJ) are new near⁃the⁃wall flow control methods for airfoils and compared with CCFJ, DCFJ is more efficient. We mainly focus on flow control effect and mechanism of DCFJ using numerical simulation. For the same jet momentum coefficient, DCFJ airfoil can achieve up to a 9�2% increase of maximum lift and simultaneously reduce aerodynamic drag. For the same power consump⁃tion, DCFJ is more striking in drag reduction. The drag is reduced 35%compared with CCFJ at zero angle of attack. The aerodynamic performance of airfoil is enhanced significantly. Simulation results and their analysis indicate pre⁃liminarily that a DCFJ airfoil generates both streamwise and spanwise vortex structures to mix the high speed jet with main flow and boundary layer thoroughly. Because of this mixing, DCFJ is highly efficient and more effective for in⁃creasing lift and reducing drag.%连续型和离散型协同射流是一种新型的翼型近壁面流动控制技术，相比之下，离散型能够更为高效地对流动进行控制。为探究离散型协同射流能耗更低、效率更高的原因，通过数值模拟方法重点研究了施加离散型协同射流的翼型流动控制效应与规律。计算结果表明在相同喷口动量系数下，与连续型相比，离散型最大升力系数提高9�2％，阻力极大减小；消耗相同功率时，离散型减阻效果明显高于连续型，零度迎角时阻力约小35％，翼型升阻特性提升更加显著。对流场的详细分析表明，离散型协同射流同时在流向和展向产生相干涡结构，使高速度的射流与主流以及边界层充分混合，因此离散型协同射流具有更好的翼型增升减阻效果和更高的能量利用率。