The Effects of Stratification on Flow Separation
The Effects of Stratification on Flow Separation
复制标题
分层对流动分离的影响
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
D. Marshall
中科院分区：
文献类型：
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作者：
M. Ambaum;D. Marshall
附面层外流动的加速或减速抑制或促进了二维山丘上分层流动的分离。在本注中，推导出了用流线曲率和分层来表示这种加速或减速的表达式。该表达式既适用于流体的线性变形，也适用于非线性变形。对于纵横比消失的山丘，可以推导出线性理论，并可以构造出完整的分离状态图。对于长径比有限的山丘，可以推导出尺度关系，表明存在一个与分层成正比的临界长径比，超过这个临界长径比将发生分离，以及第二个临界长径比，超过这个临界长径比，无论分层如何，分离总是会发生。
Abstract Separation of stratified flow over a two-dimensional hill is inhibited or facilitated by acceleration or deceleration of the flow just outside the attached boundary layer. In this note, an expression is derived for this acceleration or deceleration in terms of streamline curvature and stratification. The expression is valid for linear as well as nonlinear deformation of the flow. For hills of vanishing aspect ratio a linear theory can be derived and a full regime diagram for separation can be constructed. For hills of finite aspect ratio scaling relationships can be derived that indicate the presence of a critical aspect ratio, proportional to the stratification, above which separation will occur as well as a second critical aspect ratio above which separation will always occur irrespective of stratification.