Counter Rotating Vortices

Counter Rotating Vortices

A common method to enhance convective heat transfer is to utilize vortex-generating compact slender structures. When a vortex generator is placed in the streamwise direction of a flowing fluid, a pressure drop develops between the mean flow of the fluid and the wake region immediately downstream from the vortex generator. This pressure drop gives rise to a counter-rotating vortex pair (CVP). This CVP is a primary structure within the wake that governs and enhances mixing, while improving the heat transfer coefficient. The figure on the left shows the formation of a CVP as the fluid flows over a rectangular vortex generator located at x = -50 mm. The vectors show the fluid forming two distinct circulation zones that mirror one and other. The figure on the right shows that the CVP (shown with vorticity iso-sufaces) is prevalent in the near-wake for a significant distance downstream from the vortex generator until it eventually takes a more complex form downstream. By better understanding turbulent flows and vortex behavior, the overall efficiency of heat transfer can be greatly improved.

Allison Gibson

2016

Leonardo P. Chamorro

Copyright 2016 Allison Gibson

Mechanical Science

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