展向行波状Lorentz力的波数对壁湍流控制的影响  

Effect of Wave Number of Spanwise Travelling Wave-Like Lorentz Force on Wall Turbulent Control

作　　者：黄乐萍[1] 范宝春[1] 

机构地区：[1]南京理工大学弹道国防科技重点实验室,南京210094

出　　处：《宇航学报》2012年第3期305-310,共6页Journal of Astronautics

基　　金：国家自然科学基金(11172140)

摘　　要：展向行波状Lorentz力可以有效调制湍流近壁流动及减少壁面摩擦阻力。为了解行波波数在壁湍流控制中的影响,并进一步揭示该方法的减阻机理,本文利用Fourier-Chebyshev谱方法,通过直接数值模拟(DNS),对槽道湍流的展向行波状Lorentz力控制和减阻问题进行了研究,讨论了展向波数kz对近壁流动及壁面阻力的影响。结果表明,当展向行波状Lorentz力诱导的流场被用来调制固有的近壁湍流流场时,固有流场和诱导流场同时受到调制。Lorentz力的展向波数对流场调制效果具有显著影响。通过波数的选择,引进新的涡结构,可以调制条带结构的展向间距与强度,影响近壁流体的湍流猝发活动,从而调制壁面摩擦阻力的大小。Near wall turbulence and skin friction drag can be modified effectively via spanwise travelling wavy Lorentz force.In order to find out the influence of the wave number on turbulent control,and further disclose the mechanisms of turbulence suppression and drag reduction,control and drag reduction in turbulent channel flow via spanwise travelling wavy Lorentz force are investigated by direct numerical simulation（DNS） based on the standard Fourier-Chebyshev spectral method.The influences of spanwise travelling wave control parameter kz on the near wall flow structure and the skin friction drag are discussed.The results show that intrinsic and induced flows fields are modified each other when the spanwise wavy Lorentz force is utilized to modulate the near wall turbulent flow fields.The wave number kz plays an important role in the control.Lateral spacing and intensity of the streaked structures can be modified by proper kz,introducing into new streamwise vortices,and bursting events of the near wall turbulent flow will be affected, thus modulating the skin friction drag.

关 键 词：湍流控制 直接数值模拟 展向行波 LORENTZ力 减阻 

分 类 号：O357.5[理学—流体力学]