Efficiency of Scale-Similarity Model for Study of Forced Compressible Magnetohydrodynamic Turbulence

Efficiency of scale-similarity model for study of forced compressible magnetohydrodynamic turbulence is studied. The scale-similarity model has several important advantages in contrast to the eddy-viscosity subgrid closures: good reproduction of the correlation between actual and model turbulent stress tensor even when the flow is highly anisotropic, and absence of special model constants. These advantages may be very essential for study of forced magnetohydrodynamic turbulence. Numerical computations under various similarity parameters are carried out and the obtained results are analyzed by means of comparison with results of direct numerical simulation and Smagorinsky closure for magnetohydrodynamics. Linear forcing algorithm is applied to keep the characteristics of turbulence stationary in time. Influence of discrete filter shapes on the scale-similarity model is studied as well. It is shown that the scale-similarity model provides good accuracy and the results agree well with the direct numerical simulation results. The present results show that the scale-similarity model might be a useful subgrid closure for study of scale-invariance properties of forced compressible magnetohydrodynamic turbulence in the inertial range and in contrast to decaying case the scale-similarity model can serve as a stand alone subgrid model.