Kriging surrogate model applied in the mechanism study of tip leakage flow control in turbine cascade by multiple DBD plasma actuators

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 multiple plasma actuators is placed at the suction side of the cascade top to realize the tip leakage control. However, massive configurations appear when the number of plasma actuators increases, resulting in the investigation of actuator configuration for tip leakage flow control becomes a challenge. The surrogate modeling approach provides a cheap and efficient method for investigating the effect of multiple plasma actuators on the tip leakage flow control. By constructing an approximation model, tip leakage mass flow rates of all configurations are obtained in the present work. What's more, the flow structures in the tip clearance controlled by the plasma actuators are explained in the process of topological analysis. The results show that the tip leakage mass flow rate is decreasing with the number of active plasma actuators increasing. However, the decreasing would reach its limits in the process of adding plasma actuators. In the analysis of flow topology, single actuator would generate a small vortex at the suction side to cause an obstacle in the tip leakage flow. While the continuous arrangements of plasma actuator is beneficial to generate a larger obstacle in the tip clearance, which resulting in a significant reduction of m˙CFD and the promotion of Cp.