Plasma actuator is modeled as body force vectors resulting from external electric field and net charge distribution in plasma. Leading edge separation flows around NACA0015 airfoil under control of plasma actuator is simulated by Navier-Stokes equations with body force source which are solved by detached eddy simulation (DES) and delayed-detached eddy simulation (DDES). With actuator on, the separation flow reattached through an asymptotic progress in DDES simulation. An unsteady response occurs in DES due to grid induced separation.