CAJ | 학술논문

基于抛物化稳定性方程,研究了边界层中TS波及其高阶谐波的线性和非线性演化问题.由局部法和Landau展开式导出初始条件,并计算了扰动幅值和速度型等的演化过程和特征,特别是非线性的重要作用.探讨了初始幅值、压力梯度、扰动频率对扰动演化的影响及其规律,这与边界层的稳定性和转捩研究紧密相关.算例结果与全Navier-Stokes方程的直接数值模拟结果一致.
기우포물화은정성방정,연구료변계층중TS파급기고계해파적선성화비선성연화문제.유국부법화Landau전개식도출초시조건,병계산료우동폭치화속도형등적연화과정화특정,특별시비선성적중요작용.탐토료초시폭치、압력제도、우동빈솔대우동연화적영향급기규률,저여변계층적은정성화전렬연구긴밀상관.산례결과여전Navier-Stokes방정적직접수치모의결과일치.
Linear and nonlinear evolutions of TS wave and high-order harmonic waves in boundary layers are studied based on the parabolic stability equation (PSE). Initial conditions are derived by the local method with the Landau expansion. The evolution process and characteristics of the disturbance amplitude and the velocity profile, etc., especially stronger nonlinear effects, are computed by an efficient numerical method. Effects and regulations of different initial amplitudes, frequencies and pressure gradients on the evolution of disturbances are explored, which are directly relative to the stability and the transition in boundary layers. Simulation results are in good agreement with the data of the accuracy direct numerical simulation (DNS) using full Navier-Stokes equations.