Publicou 4 edições por ano
ISSN Imprimir: 1065-3090
ISSN On-line: 1940-4336
Indexed in
VISUALIZATION OF OSCILLATORY FLOW IN TAPERED TUBE
RESUMO
To clarify the flow mechanism that could enhance the gas exchange in lung system, the oscillatory flow fields in some types of tapered tubes were visualized by a laser light sheet method. The light sheet was made with a polygon-mirror scanning system of a laser beam. In the tapered section, it was observed that the vortex sheet of a Kelvin-Helmholtz type was generated at the outer edge of the tube-wall boundary layer, or that the flow separated at the diverging region and the resultant shear layer rolled up into vortices. The observed flow patterns could be classified based on the Reynolds number defined by the Stokes layer thickness and the mean velocity amplitude. The flow features were discussed from the viewpoint of flow instability related to the adverse pressure gradient in the tube flow field.