Numerical Study of Unstable T-S Waves Excited by Interaction Between Free-Stream Turbulence and 3D Localized Wall Roughness in Flat-Plate Boundary Layer
-
摘要: 采用直接数值模拟(DNS)方法,研究了在自由来流湍流与三维壁面局部粗糙作用下平板边界层内诱导产生不稳定T-S波的物理问题.数值结果可知,在平板边界层内发现了二维和三维T-S波组成的波包空间序列以及求得了波包向前传播的群速度大小,从而证明了自由来流湍流与三维壁面局部粗糙作用是激励平板边界层内诱导产生不稳定T-S波的一种机制.随后,建立了平板边界层内被激发的二维和三维TS波的初始幅值与自由来流湍流度,三维壁面局部粗糙的流向长度、展向宽度及法向高度之间的关系.这一问题的深入研究,进一步完善了流动稳定性与湍流理论.Abstract: The direct numerical simulation (DNS) method was adopted to study the physical problem of unstable Tollmien-Schlichting (T-S) waves in the flat-plate boundary layer under the interaction between free-stream turbulence and 3D localized wall roughness. The numerical results show that the spatial arrays of the wave packets composed of 2D and 3D T-S waves form in the flat-plate boundary layer, with the propagation speeds of the wave packets calculated. Then it is proved that the interaction between the free-stream turbulence and the 3D localized wall roughness makes the mechanism for excitation of unstable T-S waves in the flat-plate boundary layer. Subsequently, the relations between the initial 2D & 3D T-S wave amplitudes and the free-stream turbulence intensity, the roughness length, the roughness width and the roughness height, were built. The in-depth research of this problem is conducive to understanding of the hydrodynamic stability theory.
-
[1] Saric W S, Reed H L, Kerschen E J. Boundary-layer receptivity to freestream disturbances[J]. Annual Review of Fluid Mechanics,2002,34(1): 291-319. [2] Goldstein M E. Scattering of acoustic waves into Tollmien-Schlichting waves by small streamwise variations in surface geometry[J]. Journal of Fluid Mechanics,1985,154: 509-529. [3] Saric W S, Hoos J A, Radeztsky R H. Boundary-layer receptivity of sound with roughness[J]. Boundary Layer Stability and Transition to Turbulence,1991,1: 17-22. [4] Wiegel M, Wlezien R. Acoustic receptivity of laminar boundary layers over wavy walls[C]//3rd Shear Flow Conference, Shear Flow Conference.Orlando, FL, 1993: AIAA-93-3280. [5] WU Xue-song. On local boundary-layer receptivity to vortical disturbances in the free stream[J]. Journal of Fluid Mechanics,2001,449: 373-393. [6] Dietz A J. Local boundary-layer receptivity to a convected free-stream disturbance[J]. Journal of Fluid Mechanics,1999,378: 291-317. [7] Choudhari M, Kerschen E J. Instability wave patterns generated by interaction of sound waves with three-dimensional wall suction or roughness[C]//28th Aerospace Sciences Meeting . Reno, NV, 1989. [8] Tadjfar M, Bodonyi R J. Receptivity of a laminar boundary layer to the interaction of a three-dimensional roughness element with time-harmonic free-stream disturbances[J]. Journal of Fluid Mechanics,1992,242: 701-720. [9] Zhou M D, Liu D P, Blackwelder R F. An experimental study of receptivity of acoustic waves in laminar boundary layers[J]. Experiments in Fluids,1994,17: 1-9. [10] Würz W, Herr S, Wrner A, et al. Three-dimensional acoustic-roughness receptivity of a boundary layer on an airfoil: experiment and direct numerical simulations[J]. Journal of Fluid Mechanics,2003,478: 135-163. [11] Würz W, Herr S, Wrner A, et al. Study of 3D wall roughness acoustic receptivity on an airfoil[M]// Laminar-Turbulent Transition . Berlin, Heidelberg: Springer, 2000: 91-96. [12] 陆昌根, 沈露予. 壁面局部吹吸边界层感受性的数值研究[J]. 物理学报, 2015,64(22): 224702. doi: 10.7498/aps.64.224702.(LU Chang-gen, SHEN Lu-yu. Numerical study on boundary-layer receptivity with localized wall blowing/suction[J]. Acta Physica Sinica,2015,64(22): 224702. doi: 10.7498/aps.64.224702.(in Chinese)) [13] SHEN Lu-yu, LU Chang-gen. Boundary-layer receptivity under interaction of free-stream turbulence and localized wall roughness[J]. Applied Mathematics and Mechanics(English Edition),2016,37(3): 349-360. [14] SHEN Lu-yu, LU Chang-gen. Local receptivity in non-parallel boundary layer[J]. Applied Mathematics and Mechanics(English Edition),2016,37(7): 929-940. [15] 陆昌根, 沈露予. 无限薄平板边界层前缘感受性过程的数值研究[J]. 物理学报, 2016,65(19): 194701. doi: 10.7498/aps.65.194701.(LU Chang-gen, SHEN Lu-yu. Numerical study of leading-edge receptivity on the infinite-thin flat-plat boundary layer[J]. Acta Physica Sinica,2016,65(19): 194701. doi: 10.7498/aps.65.194701.(in Chinese)) [16] 沈露予, 陆昌根. 三维边界层内定常横流涡的感受性研究[J]. 物理学报, 2017,66(1): 014703. doi: 10.7498/aps.66.014703.(SHEN Lu-yu, LU Chang-gen. Receptivity of the steady cross-flow vortices in three-dimensional boundary layer[J]. Acta Physica Sinica,2017,66(1): 014703. doi: 10.7498/aps.66.014703.(in Chinese)) [17] 沈露予, 陆昌根. 边界层流中当地感受性过程的数值研究[J]. 应用数学和力学, 2016,37(11): 1156-1168.(SHEN Lu-yu, LU Chang-gen. Numerical study of local receptivity in the boundary layer[J]. Applied Mathematics and Mechanics,2016,37(11): 1156-1168.(in Chinese)) [18] SHEN Lu-yu, LU Chang-gen, WU Wei-guo, et al. A high-order numerical method to study three-dimensional hydrodynamics in a natural river[J]. Advances in Applied Mathematics and Mechanics,2015,7(2): 180-195. [19] LU Chang-gen, CAO Wei-dong, ZHANG Yan-mei, et al. Large eddies induced by local impulse at wall of boundary layer with pressure gradients[J]. Progress in Natural Science,2008,18(7): 873-878. [20] ZHANG Yong-ming, Zaki T, Sherwin S, et al. Nonlinear response of a laminar boundary layer to isotropic and spanwise localized free-stream turbulence[C]//6th AIAA Theoretical Fluid Mechanics Conference.Honolulu, Hawaii, 2011.
点击查看大图
计量
- 文章访问数: 794
- HTML全文浏览量: 86
- PDF下载量: 459
- 被引次数: 0