A summary of the major theoretical models available for departure diameter prediction in sub-cooled flow boiling is presented. A new model is developed to predict the forces acting on a bubble at the instance of departure by introducing a control volume approach for the front and the rear halves of the bubble. The predictions from the model are compared with experimental data obtained in the Thermal Analysis Laboratory in the Mechanical Engineering Department at Rochester Institute of Technology. Two competing mechanisms are identified as being responsible for bubble departure. To obtain clear evidence of the dominate mechanism, high speed photography is recommended in future work in this area
