Numerical Simulation Of Self-rotation In Ferrofluid Pipe Flow Under Magnetic Field

As a new type of intelligent ?uid with its unique property of magnetism and liquid-like characteristics, ferro?uid has been received more and more attention recently from academic and engineering ?eld. It has signi?cantly potential engineering applications to study self-rotation phenomenon of the ferro?uid pipe ?ow under the magnetic ?eld. Due to the di?culty of producing strong enough magnetic ?eld in experiment, this work is mainly focusing numerical study. The present thesis mainly consists two sections, as following:Considering the physical area of pipe, numerical simulation is carried in cylindrical coordinate system. It presents the derivation of control equations based on cylindrical coordinate system and dimensionless of the equations. The physical model transform into mathematical model.The calculation area is simpli?ed to a rectangular area for symmetry of the three dimensional pipe. Three kinds of cases are numerically simulated for the simpli?ed model, without magnetic ?eld, the magnetic ?eld being constant and the magnetic ?eld being calculated by Maxwell equations. Compared numerical results of without magnetic ?eld with exact solution of G.H.L.Hagen-poiseuille ?ow,it validates feasibility of the simpli?ed model and correctness of the program. For the magnetic ?eld being constant, the simulation results show that magnetic ?eld has an impact on axial velocity but self-rotation velocity. For the magnetic ?eld being calculated by Maxwell equations, the results are congruous with theoretical results that self-rotation velocity exists and it increases with the increase of the magnetic ?eld. Besides, the relationships of self-rotation rate and the volume fraction of magnetic particles in ferro?uid , Reynolds number , the pressure di?erence of the pipe’s two ends ?, Stokes number , magnetic susceptibility are discussed respectively.