三维边界层内诱导横流失稳模态的感受性机理

发布时间：2018-04-24 00:27

本文选题：感受性 + 三维边界层　；参考：《物理学报》2017年20期

【摘要】：边界层感受性问题是层流向湍流转捩的初始阶段,在转捩过程中起关键性作用,尤其是三维边界层流动.因此,研究三维边界层感受性问题对进一步理解层流向湍流转捩机理以及湍流成因具有重要的理论意义.采用数值方法研究自由来流湍流与三维壁面局部粗糙相互作用下三维边界层的感受性问题,确定是否能在三维边界层内寻找一种新的横流失稳模态;确定在何种条件下三维边界层内能诱导出定常、非定常的横流失稳模态;探索自由来流湍流的强度、展向波数和法向波数以及三维壁面局部粗糙的大小和结构类型等因素在自由来流湍流与三维壁面局部粗糙作用下三维边界层内被激发出的感受性过程中有何影响,并确定何种横流失稳模态在三维边界层感受性过程中占据何种地位.对自由来流湍流与三维壁面局部粗糙作用激发三维边界层内感受性问题的深入研究,将有助于完善流动稳定性与湍流理论,为层流向湍流转捩过程的预测与控制提供合理的理论依据.
[Abstract]:Boundary layer receptivity is the initial stage of layer flow turbulence transition, which plays a key role in the transition process, especially in three-dimensional boundary layer flow. Therefore, the study of three-dimensional boundary layer receptivity is of great theoretical significance for further understanding the mechanism of turbulent transition in the flow direction of the layer and the origin of the turbulence. The receptivity of 3D boundary layer under the interaction of free flow turbulence and local roughness of 3D wall is studied by numerical method, and it is determined whether a new mode of transverse flow instability can be found in 3D boundary layer. To determine the conditions under which steady and unsteady transverse flow instability modes can be induced in the three-dimensional boundary layer, and to explore the intensity of free flow turbulence. How do the factors such as spanwise wavenumber and normal wavenumber and the size and structure type of local roughness of 3D wall affect the receptivity of 3D boundary layer excited by free flow turbulence and 3D wall local roughness? The position of the transverse flow instability mode in the three dimensional boundary layer receptivity is determined. The deep study of the receptivity problem in the three-dimensional boundary layer excited by the free flow turbulence and the local roughness of the three-dimensional wall will help to perfect the theory of flow stability and turbulence. It provides a reasonable theoretical basis for prediction and control of laminar turbulent transition.
【作者单位】：南京信息工程大学海洋科学学院;
【基金】：国家自然科学基金(批准号:11472139) 江苏高校优势学科建设工程(批准号:PAPD) 南京信息工程大学人才启动基金(批准号:2016r046)资助的课题~~
【分类号】：O357.5

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