Conically similar viscous flows. Part 3. Characterization of axial causes in swirling flow and the one-parameter flow generated by a uniform half-line source of kinematic swirl angular momentum
Conically similar viscous flows. Part 3. Characterization of axial causes in swirling flow and the one-parameter flow generated by a uniform half-line source of kinematic swirl angular momentum
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DOI：
10.1017/s0022112085001859
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发表时间：
1985-06
影响因子：
3.7
通讯作者：
R. Paull;A. F. Pillow
中科院分区：
文献类型：
--
作者：
R. Paull;A. F. Pillow
在本系列的第一部分中，我们发展了一般轴对称不可压缩粘性流的环形环量守恒原理和运动涡旋角动量守恒原理。这些原则，然后被用来分类的四个独立的轴向原因的无旋锥形相似的粘性流。第2部分详细分析了由每个轴向奇点单独作用所产生的单参数无旋流。本文将驱动轴对称粘性流的轴向奇异性的描述扩展到旋流。在锥形相似粘性流的特殊情况下，两个独立的半线源的旋流角动量足以完成的轴向奇点，可以产生这样的旋流。六个独立的轴向原因的单独强度提供了可以以这种方式产生的所有锥形相似粘性流的完整表征。第3部分通过研究在半轴上均匀产生运动涡旋角动量所引起的流动，完成了详细分析由轴向原因产生的独立单参数流动的任务。该流动演示了涡流如何引起轴向半平面流动。对于大的涡流循环强度，涡流角动量扩散和对流，以便以几乎恒定的涡流角动量密度填充略多于一半的空间。一个发展良好的内附面层，以向外的径向喷流的形式，然后将这个区域与几乎无旋的流动区域分开。射流夹带两个碰撞对流场。射流的角位置是通过将在原点产生的旋转力矩的轴向分量与轴上的旋转循环奇点的强度相关联来确定的。
In Part 1 of this series conservation principles for ring circulation and kinematic swirl angular momentum were developed for general axisymmetric incompressible viscous flow. These principles were then used to classify the four independent axial causes of swirl-free conically similar viscous flow. Part 2 provided a detailed analysis of the one-parameter swirl-free flows that are generated by each one of the axial singularities acting alone. The present paper extends, to swirling flow, the description of the axial singularities that drive axisymmetric viscous flow. In the special case of conically similar viscous flow, two independent half-line sources of swirl angular momentum suffice to complete the set of axial singularities that can generate such swirling flows. The individual strengths of the six independent axial causes provide a complete characterization of all conically similar viscous flows that can be generated in this way. This Part 3 completes the task of analysing in detail the independent one-parameter flows generated by axial causes by studying the flow caused by uniform production of kinematic swirl angular momentum on a half-axis. This flow demonstrates how swirl may induce an axial half-plane flow. For large swirl circulation strengths, swirl angular momentum diffuses and convects so as to fill slightly more than half the space with an almost constant density of swirl angular momentum. A well-developed internal boundary layer, in the form of an outward radial jet, then separates this region from one in which the flow is almost irrotational. The jet entrains two impinging convection fields. The angular location of the jet is determined by relating the axial component of moment of whirl produced at the origin to the strength of the swirling circulation singularity on the axis.