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后掠机翼边界层流动稳定性及转捩对翼型的设计及优化有着重要的参考价值,而机翼后掠角是引起后掠机翼边界层横流失稳的关键参数之一.以NACA0012翼型为研究对象,通过求解三维可压缩Navier-Stokes方程计算了展向无限长后掠机翼的基本流场;通过求解Orr-Sommerfeld方程得到了扰动Tollmien-Schishting波演化的中性曲线及幅值曲线,研究了后掠角对后掠机翼边界层流动稳定性的影响;最后采用e N方法进行了转捩预测.研究发现,随后掠角的增大,横流强度和扰动幅值放大指数n均先增加后减小,且后掠角在40°~50°之间横流强度达到最大值.当后掠角在50°左右时,用转捩预测e N方法计算的幅值增长指数N值最大,导致转捩发生所需的初始扰动幅值最小,转捩最易发生.
Swept wing boundary layer flow stability and rotation of the airfoil design and optimization has important reference value, and wing sweep angle is caused by the sweepback wing boundary layer cross-flow instability of the key parameters of NACA0012 Airfoil as the research object, the basic flow field of the infinite swept wing is calculated by solving the three-dimensional compressible Navier-Stokes equation. The neutral curve and the amplitude of the disturbed Tollmien-Schishting wave are obtained by solving the Orr-Sommerfeld equation Value curves were used to study the effect of sweep angle on the flow stability of the swept wing boundary layer. Finally, the eN method was used to predict the transition.It was found that with the increase of sweep angle, the cross-flow intensity and the magnification index n increases first and then decreases, and the sweep intensity reaches the maximum value between 40 ° and 50 ° .When the sweep angle is about 50 °, the amplitude growth index N The value of the maximum, resulting in the minimum initial disturbance required for the transition occurs, the transition is most likely to occur.