- A two-fluid model was used to model and simulate the flow of an organic binary mixture through a generator and a bubble pump tube. Both thermal and non-thermal equilibrium conditions were examined. Results obtained from a steady state steady flow experimental system operated with R22-DMAC (chlorodifuoromethane-NN'dime-thylacetamide) as working fluids were used to validate the predictions of the numerical simulations. The predictions of the numerical simulations for various heat sources on the flow characteristics were compared with the experimental results. Based on the numerical simulations detailed description of the flow characteristics inside the generator and the bubble pump tube were obtained.