Turbulent Flow Measurements behind an Attached Ring-Type Manipulator in Turbulent Pipe Flow.

Abstract

The response of a fully developed turbulent pipe flow, in which air was flowing at Reynolds number of 6.2×104, to a pulsewise disturbance due to an attached ring-type manipulator with rectangular cross section, was investigated by measuring turbulent flow field. The results indicate that the response of turbulence flow field delayed as compared with that of mean flow field. Close to the wall, the values of turbulence intensities and Reynolds shear stress profiles definitely decrease being incidental to the decrease of wall shear stress. Whereas at the locus of a ring height all the turbulence quantities take a peak value based on the development of the separated shear layer. The separated shear layer accompanying with the separation and the reattachment process have a intermediate feature between the case of upstanding roughness and downward step. Present flow field disturbed by the ring-type manipulator is classified into six region determined from the mean flow and turbulence flow characteristics.