Saturated Pool Boiling Heat Transfer of Toluene-Solvent Magnetic Fluid on a Horizontal Surface. Effects of Field Gradient, Concentration of Particles, and Pressure.

Abstract

Saturated pool boiling heat transfer of a toluene-solvent magnetic fluid containing magnetite particles of 0∼36.5 wt% was investigated on a horizontal surface in a vertical magnetic field and field gradient at the pressure of 0.021∼0.061MPa. In the absence of a magnetic field gradient, the heat transfer was enhanced significantly for magnetic fluid with dilute magnetite particles, while it was reduced for that with dense particles. As the magnetic field gradient was increased up to 3.9 x 105 A/m2, the heat transfer of the dense magnetic fluid was enhanced significantly in a low heat flux region, although it returned to the reduced heat transfer curve slowly at a certain transition heat flux. The transition heat flux increased, as the magnetic field gradient became higher, the magnetite concentration lower, and the pressure higher.