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Electrohydrodynamic actuator is one of the newest devices in flow control techniques which can delay separation point and reduce the drag coefficient by inducing external momentum to the boundary layer of the flow. In this paper, a 2-D numerical approach was implemented to analyze the presence of electrohydrodynamic actuator on the incompressible, turbulent, steady flow over a NACA 4412 asymmetric airfoil. In this regards, the flow field and aerodynamic characteristics such as the drag and pressure coefficient were evaluated through the variety of attack angles, applied voltages, the location of emitting electrode, and the distance from the upper surface of the airfoil. The numerical results indicate that the drag coefficient with the presence of an electric field decreases with the enhancement of the supplied voltage but increases when the attack angle is augmented. In addition, the location of separation point significantly depends on the position of emitting electrode and the distance between the emitting electrode and the collecting electrode. On the other hand, according to the results, the Electrohydrodynamic effects cause the diminution of the wake region over the airfoil.

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In this paper, the flow and temperature fields affected by electrohydrodynamic actuator are numerically investigated for the incompressible, turbulent, and steady flow over a backward-facing step. Air is used as working fluid in heated backward-facing step cooling process. The electric field is generated by the wire electrode charged with DC high voltage. The numerical modeling is based for solving electric, flow, and energy equations with finite volume approach. The computed results are firstly compared with the experimental data in case of rectangular flat channel and the results agree very well. Then the effect of different parameters such as the radius of the wire, applied voltage, Reynolds number, and the wire position on the heat transfer coefficient is evaluated. The results show that the heat transfer coefficient with the presence of electric field increases with the applied voltage but decreases when the Reynolds number and the radius of the wire are augmented. Moreover, reduction of emitting electrode angle can significantly effect on the heat transfer enhancement. In consequence, one may able to find an optimum place for the emitting electrode position.

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Plasma actuator is one of the newest ways in vortex generation and flow control techniques which can enhance heat transfer rate by inducing external momentum to the boundary layer of the flow. In this paper, a 2-D numerical approach was implemented to analyze the presence of plasma actuator on the incompressible, turbulent, steady flow in a flat channel. In this approach, the flow field and heat transfer characteristics such as the stream function and heat transfer coefficient were evaluated through the variety of Reynolds number, at the presence and absence of applied voltages. The present computed results are firstly compared with the numerical data in case of rectangular flat channel and the results agree very well. The numerical results indicate that at a constant Reynolds number with the presence of a plasma actuator, the heat transfer coefficient will be increased but in a constant applied voltage the heat transfer coefficient will increase to the Reynolds of 250 and then will be decreased respectively. In addition, the size of generated vortexes significantly depends on the applied voltage and the upstream flow speed. On the other hand, according to the results, the flow speed affects the size of generated vortex and vanish the actuator effect at high Reynolds. According to the results, there is an optimized point for the applied voltage and flow speed.