战斗机垂尾脉动压力数值模拟

Numerical simulation of fluctuating pressure of fighter vertical tail

在亚跨超计算流体力学(CFD)软件平台(TRIP)上开发了基于RANS/LES混合思路的IDDES流动模拟技术,并通过NACA0021翼型60°大迎角分离流动与串列圆柱绕流模拟对RANS/LES混合方法的精确度进行了验证,针对某战斗机外形的垂尾脉动压力开展了数值模拟研究。战斗机来流马赫数为0.1,基于全机长度的雷诺数为2×106,模型迎角为20°、30°和40°。分别通过脉动压力系数、脉动压力功率谱密度、空间流动结构以及侧向力响应曲线等对战斗机的垂尾脉动压力进行了分析。脉动压力模拟结果表明:当垂尾完全沉浸在边条翼脱体涡破碎后的宽频湍流脉动气流中时,垂尾翼梢位置的脉动压力会发生明显的增大。

IDDES flow simulation technique based on hybrid RANS/LES method is realized on TRIP,a trisonic fluid simulation software platform.Separating flows around airfoil NACA0021 with 60°angle of attack and tandem cylinders are simulated to validate the precision of hybrid RANS/LES method.Then,fluctuating pressure of a fighter vertical tail is calculated with the presented RANS/LES method.Flow Mach number is 0.1,Reynolds number based on length of fighter is 2million,and angles of attack are 20°,30°and 40°.Fluctuating pressure of fighter vertical tail is analyzed through fluctuating pressure coefficients,power spectrum density of fluctuating pressure,space flow structure and side force response.Numerical results show that fluctuating pressure on tip of vertical tail increases obviously when vertical tail is immersed in broadband turbulence fluctuating flow behind the breakup of separating vortex from strake wing.