Parameters Identification Of DBD Plasma Model Based On Kriging Model And Its Application

With the plasma actuators is widely used in the flow control,the research about the influence of the actuators to the flow become more deeply.The simulation is such an important method to study the plasma.The multiple processes of plasma actuation complete in different time scales and the time span is about 106.The huge time span make it difficult to solve the plasma actuation.To deal with the difficult,in general,it need to simplify the process with some hypothesis.And then the equivalent model will be established.But there are certain empirical parameters in the DBD(dielectric barrier discharge)plasma actuators modeling,and these parameters need to be calibrated through some special experimental result.Taking the model of Shyy as an example,in order to reduce the error caused by the empirical parameters,parameters identification method will be used in parameters calibration.A more accurate parameters of the model for this process of plasma will be generated.Firstly,the boundary shape and maximum electric field intensity of plasma action area in Shyy's model are taken as identification parameters.After that,the orthogonal experimental design is used to establish the sample matrix.In addition,the Kriging method is used to establish a surrogate model to replace the actual physical process.Finally,the model parameters are optimized by genetic algorithm,and the new model parameters are obtained.Through the analysis of the identification parameters,it is found that the new identification parameters give a new shape of the boundary curve,which is a curve of upper convex and lower concave.The maximum electric field intensity E0 is positively proportional to the peak voltage U,E0=290U-1.16×106.The simulation results obtained using the new model parameters are better than those obtained by the original model.Using the new model,we calculated the flow in the blade cascade with a blademounted DBD actuator.The detail of the flow,as well as the improvement of cascade leakage loss and analyzes the effects of convection field exciter details.Actuator in the tip clearance produces the body forces,which makes the low energy fluid near the boundary layer accelerate reversely.The accelerated fluid meets the main flow in the suction side of the blade tip,forming a new vortex structure,reducing the leakage height and leakage rate effectively.With the decreasing of the leakage rate,the size of the leakage vortex also decreases.The suppression of the leakage vortex to the passage vortex is weakened,so the passage vortex is bigger and move upward.The stagnation loss caused by leakage vortex and passage vortex are decreased and increased respectively.And the stagnation loss caused by the leakage vortex thus decreases significantly,thus the total loss decreases.In the end of the tip,the body force produced by the actuator is much greater than the pressure difference between pressure side and suction side.Therefore there exists a reverse leakage,which bring some negative influence.But it can be resolved by reducing the length of the actuator.