Magnetic Control of Convection in Nonconducting Diamagnetic Fluids

Inhomogeneous magnetic fields exert a body force on electrically nonconducting, diamagnetic fluids. This force can be used to compensate for gravity and to control convection. The field effect on convection is represented by a dimensionless vector parameter Rm=(μ0αχ0d3ΔT/ρ0νDT)(H⋅∇H)r=0ext, which measures the relative strength of the induced magnetic buoyancy force due to the applied field gradient. The vertical component of this parameter competes with the gravitational buoyancy effect and a critical relationship between this component and the Rayleigh number is identified for the onset of convection. Magnetically driven convection should be observable even in pure water using current technology