SPH simulation of transition to turbulence for planar shear flow subjected to a streamwise magnetic field

Active flow control of electrically conducting fluids finds growing importance in the metallurgical industry. A magnetic field applied in the streamwise direction of electrically conducting fluid flow restrains the velocity fluctuations in the transverse plane and the transition to turbulence may be delayed. The smoothed particle hydrodynamic (SPH) methodology is employed to interpret this concept. To this purpose, the onset of turbulence is related to the transitional organization of the SPH fluid particle structure or to the temporal history of the turbulence-related quantities during the early stages of the transition to turbulence. The results put in evidence the ability of a streamwise magnetic field on controlling the transition to turbulence of an electrically conducting fluid flow, i.e., the transition to turbulence may be distinctly delayed in the fluid flow subjected to a streamwise magnetic field. Furthermore, if the applied streamwise magnetic field is strong enough, the Reynolds stress in the streamwise direction may be dominant over the transverse counterpart, and turbulence is anisotropic as only in the streamwise direction of the fluid flow, the Reynolds stress is detectable.