Flow and Heat Transfer Characteristics of Turbulent Boundary Layer With Control

The flow and heat transfer characteristics of turbulent flow in rectangular channel were researched by using the numerical simulation method.The wall-normal and spanwise fluctuating velocities of fully developed turbulent boundary layer were controlled respectively.The flow and heat transfer characteristics of channel flow with control were studied.A comparison of simulation results with the direct numerical simulation results of Kim et al.shows good agreement.The heat transfer surface Nusselt number was compared to the Nusselt number which was calculated by Gnielinski equation.The goal of drag reduction can be achieved by controlling fluctuating velocity of boundary layer.The control method adopts the way of controlling positive wall-normal fluctuating velocity of strip areas in the boundary layer to 0 and the 0.1,0.2,0.3 times of original fluctuating velocity,and adopts the way of controlling spanwise fluctuating velocity of strip areas to 0.But as the drag reduction effect increases the heat exchange performance of channel heat transfer surface gradually weakens.