Periodic Behavior of Longitudinal Vortices Downstream of an Active Vortex Generators Pair (Response of High Velocity Tongue to the Height of AVG and Development of Rotating X-array Hot-wire anemometer)

Abstract

This paper is focused on the high velocity tongue beneath the longitudinal vortices downstream of a pair of active vortex generators (AVG) with common flow up configuration. An active control of turbulent boundary layer separation is one of the most interesting projects. It is important to achieve a smart control system based on the detailed information of time depended characteristics of the longitudinal vortices. Phase averaged mean velocity is measured by a newly developed rotating X-array hot-wire anemometer. The high velocity tongue shows rapid response to the height of the AVG at the final-stage of up-phase compared with the early-stage of down-phase. The transportation of high velocity fluid beneath the longitudinal vortices plays an important roll on the response of longitudinal vortices.