细长旋成体大迎角俯仰振荡的数值研究

为研究俯仰振荡对细长旋成体流场与气动特性的影响，利用雷诺平均方法与大涡模拟的混合方法相结合的脱体涡模拟方法对大迎角下细长旋成体俯仰运动进行了数值模拟研究。通过对背风面分离涡的强度和位置、细长体绕流形态、截面压强系数和侧向力系数的观察和分析，发现施加小振幅、特定频率的俯仰振荡对大迎角细长旋成体背风面流场有明显的控制能力，...

Numerical Research on Pitching Oscillation Characteristic about a Slender Body at High Angle of Attack

The separated flow of the slender under the influence of pitching oscillation at high angle of attack are simulated numerically using DES （detached-eddy simulation） approach, which is theoretically a good way of taking advantage of the merits of both RANS （Reynolds averaged Navier-Stokes） and LES （large eddy simula- tion） methods. The asymmetric flows observed in experiment are simulated successfully by the introduction of a small bump placed near the body apex. The location and strength of separated vortex, flow field, pressure dis- tribution on the surface and force coefficients are observed and analyzed. It is found that, the pitching oscillation at fixed frequency has strong control ability to the slender body at high angles of attack, and it will change the construction of flow field, the asymmetric flow is restrained and tends to symmetric flow. The higher the ampli- tude of pitching oscillation, the more obvious of restraining function. Increasing oscillation frequency is effective for the inhibition of asymmetry. Consequently the results are useful to the application of unsteady aerodynamic forces.