细长机翼摇滚的数值模拟及物理特性分析

NUMERICAL SIMULATION AND PHYSICAL CHARACTERISTICS ANALYSIS FOR SLENDER WING ROCK

耦合三维非定常Navier-Stokes方程与Euler刚体运动方程数值研究80°尖前缘后掠三角翼的机翼摇滚问题.采用高精度的WNND(weightednon-oscillatory,containingnofreeparametersanddissipative)格式离散流动控制方程、采用时间二阶精度单边差分离散刚体运动方程数值模拟了马赫数为0.35,攻角为10°,22°,30°下三角翼受扰后的自由滚转运动.结果表明:22°攻角附近为所给三角翼出现横向不稳定的摇滚运动的临界攻角;当攻角小于临界值时,受扰后的机翼滚转运动收敛,而当攻角大于临界值时,受扰后的机翼滚转运动发散并形成极限环形式的机翼摇滚.

The unsteady, compressible, full Navier-Stokes（N-S） equations and Euler equation of rigid-body dynamics are sequentially solved to simulate the wing rock phenomenon of 80° sweep, sharp edged delta wing. The flow solver of the code involves a space third-order-accurate conservational variable WNND （weighted nonoscillatory, containing no free parameters and dissipative） scheme. The rigid-body dynamics equation is solved using a second-order-accurate finite difference scheme. The physical characteristics of freedom rolling motion of disturbed delta wing in single-DOF （degree of freedom） at 10°, 22°, 30° AoA （angle of attack） in a free stream of Mach number 0.35 are predicted and analyzed. The results show 22° is the critical AoA at which the wing rock phenomenon （which is a typical phenomenon of lateral-directional instability） will occur. When AoA is less than 22°, the freedom rolling motion of disturbed delta wing will converge to the equilibrium point. When AoA is greater than 22°, the freedom rolling motion of disturbed delta wing will diverge at first, and then become into the limit-cycle wing rock motion.