Heat Exchange at a Magnetic Fluid Boiling in aMagetic Field on a Horizontal Surface with a Point Heater

Abstract

This paper deals with an effect of a uniform magnetic field on heat transfer during the bub-ble boiling of a magnetic fluid on a horizontal surface with a point heater. Boiling curves are obtained for magnetic fluids with a volume concentration of a solid phase 12%, 8%, and 5.5% in magnetic fields of various strengths. It was found that the curves are non-monotonic. The magnetic field strength corresponding to the maximum heat flux was determined. The effect of the magnetic field on the heat flux increases when the concentration of the sol-id phase increases. In addition, an equation that satisfactorily described the experimentally observed effect of the magnetic field on the heat flow at bubble boiling mode using an approximate theory for boiling fluids heat transfer was derived. Also the forces acting on a vapor bubble in a nonuniformly heated magnetic fluid were analyzed.