Experiment and simulation of laminar and turbulent ferrofluid pipe flow in an oscillating magnetic field.

Laminar and turbulent pipe flow of a ferrofluid with an imposed linearly polarized, oscillating, magnetic field is examined here. Experimental results show a fractional pressure drop dependence on flow rate, magnetic field strength, and oscillation frequency. Calculations are presented, which show that ferrofluid theory can explain the flow phenomena in laminar and turbulent pipe flow. The model requires an initial fit of key parameters but then shows predictive capability in both laminar and turbulent flow. Simulation results are found to be essentially independent of the spin boundary condition due to an approximation of spin viscosity that is very small. A low Reynolds number k-epsilon model is used to model the turbulent pipe flow.