Department of Mechanical Engineering, Isfahan University of Technology, Isfahan, 8415683111, Iran
Film boiling has various industrial applications especially in heat exchangers. Studying this phenomenon on complex geometries and investigating heat transfer coefficient is desired by many industries. The numerical method used here is a finite difference/front tracking method which is developed independently for film boiling in complex geometries. The film boiling over one, two or more cylinders is simulated using this method. The effect of dimensionless parameters namely Grashof and Jacob numbers are investigated for one cylinder. The effects of spacing, angle, and diameter are investigated for two cylinders. For the case with many cylinders, the effects of different geometrical configurations (regular and staggered) and number of rows are investigated by calculating the average Nusselt number on each cylinder. It is observed that the cylinder spacing does not have any significant effect on the Nusselt number for the upper cylinder. However the angle and cylinder diameter significantly affect the Nusselt number for the upper cylinder. In regular configuration, the Nusselt numbers for the upper cylinders are relatively uniform and higher than lower cylinders. In the staggered configuration, however, the Nusselt numbers of the upper cylinders are different, non-uniform, and higher than those of the regular arrangement.