...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>ZAMP: Zeitschrift fur Angewandte Mathematik und Physik: = Journal of Applied Mathematics and Physics: = Journal de Mathematiques et de Physique Appliquees >The critical cross-section of a vortex
【24h】

The critical cross-section of a vortex

机译：涡旋的临界截面

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

This paper discusses the problem of critical-flow cross-sections in vortex flows. It is shown that there are two different types of vortex flows. A-type and B-type vortices (say). An A-type vortex approaches its critical flow state as its cross-sectional area increases and departs from the dritical state as the pressure and circulation on the stream function, and it holds for both subcritical and supercritical A-type vortices. On the other hand, both subcritical and supercitical B-type vortices approach their critical flow states as their cross-sectional areas are decreased and depart from their critical states for increasing cross-sectiona area. As was shown by Benjamin, setting the first variation of the flow force with respect to the stream function equal to zero leads to Euler's equation of motion. The second variation also vanishes if the corresponding flow state is critical. In this case the sign of the third variation decides whether the flow is an A-type or a B-type vortex. Within the framework of inviscid-fluid flow theory the type of a vortex is preserved unless vortex breakdown occurs. Making use of the knowledge that vortex flows are controlled by two different types of critical-flow cross-sections a variety of vortex flow phenomena are investigated, including the two types of inlet vortices that are observed upstream of jet engines, the behavior of vortex valves, the flow characteristics of liquid-fuel atomizers and the bath tub vortex.
机译：本文讨论了涡流中的临界流横截面问题。结果表明，存在两种不同类型的涡流。 A型和B型涡旋（例如）。随着流的压力和循环作用，A型涡流的横截面积增大，其接近临界流动状态，并且偏离干态，并且对于亚临界和超临界A型涡流均适用。另一方面，随着亚临界B型涡流和超临界B型涡流的横截面面积减小，它们逐渐接近其临界流动状态，并偏离临界状态，从而增加了横截面面积。如本杰明所示，将流力相对于流函数的第一变化设置为零会导致欧拉运动方程。如果相应的流动状态很关键，则第二种变化也将消失。在这种情况下，第三变化的符号决定了流动是A型涡流还是B型涡流。在无粘性流体流动理论的框架内，除非发生涡旋破坏，否则涡旋的类型将得以保留。利用涡流受两种不同类型的临界流横截面控制的知识，研究了各种涡流现象，包括在喷气发动机上游观察到的两种类型的进气涡流，涡流阀的性能，液体燃料雾化器的流动特性和浴缸涡流。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号