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.