## K_PF_1999

# Vorticity Flux Control in a Turbulent Channel Flow

Koumoutsakos P., *Physics of Fluids*, 11, 2, 248-250, 1999.

**ABSTRACT **

A feedback control algorithm using wall only information has beenapplied in simulations of low Reynolds number (Re-tau = 180) turbulentchannel flow. The present control scheme is based on the manipulationof the vorticity flux components, which can be obtained as a functionof time by measuring the instantaneous pressure at the wall andcalculating its gradient. The strength of the unsteady masstranspiration actuators can be derived explicitly by inverting a systemof equations whose terms depend on the relative locations of thesensors and actuators. The results of the simulations indicate a large(up to 40%) drag reduction. Moreover it appears that using the presentmethodology open-loop control laws can be devised. (C) 1999 AmericanInstitute of Physics.