According to the aerodynamics momentum and energy equations

the similarity criteria of body force and releasing heat induced by surface dielectric barrier discharge plasma flow control were studied on the basis of the similarity theory. The body force similarity criterion is essentially Reynolds number similarity which has three forms according to the experimental conditions. When the air is quiescent

the Reynolds number can be obtained using the maximal velocity and jet half height of induced jet. For free stream

the force unit length similarity based on the force unit length

free stream velocity

and kinetic viscosity coefficient can be used

or the velocity-modified Reynolds number similarity can be applied that the Reynolds number in quiescent air is modified b

y the maximal velocity of induced jet and free stream velocity. The releasing heat similarity criterion is dimensionless perturbation pressure similarity. The velocity-modified Reynolds number similarity is used to simulate the S1223 airfoil plasma flow control at altitude 20 km. It is found that when the angle of attack is positive and the Reynolds number is low

the lift coefficient will increase by about 10%

5

5% even if the angle of attack is quite high. The flow fields on up and down surfaces of airfoil are modified by plasma. But when the free stream Reynolds number is high

plasma acts weakly.