Large Eddy Simulation of the Elliptic Jets in Film Cooling Controlled by Dielectric Barrier Discharge Plasma Actuators With an Improved Model

Abstract

The dielectric barrier discharge (DBD) plasma actuator, in which electrodes are asymmetric arranged, has already demonstrated its ability in flow control. In the present work, the configuration of DBD plasma actuator defined as DBD-vortex generator (VGs), which can induce streamwise vortices, has been employed in the flow control of the inclined jet in crossflow. The coherent turbulent structures around the cooling hole are examined by the large eddy simulation (LES) method with the improved plasma model. The mechanism of coherent structure controlled by the DBD-VGs is also elucidated in the processes of parametric study with the actuation conditions. The calculation results show that the DBD-VGs provides us an effective approach to further enhance the performance of the film cooling. When it is applied into the flow, symmetrical streamwise vortices are induced to break down the coherent vortex structure, leading to more coolant gathered on the surface, especially at the lateral area of the coolant jet. What is more, an overall improvement of the film cooling performance can be obtained when the actuation strength is strong enough.