Abstract
A reliable numerical procedure using the control volume formulation has been built up for predicting the hydrogen-generation process. The hydrogen production is due to the flow of an electrolyte between cathode and anode at different current densities. A bubbly two-phase flow process has been considered and a mathematical model based on Eulerian-Eulerian two-fluids has been adopted. The transport equations have been solved for both phases with allowance of interfacial transfer of mass and momentum. The conservation equations have been discretized using a finite volume method and solved by the SIMPLE algorithm. Measurements have been carried out along a tested cell gap at different current densities to visualize the hydrogen generation process. New insights into the model of hydrogen bubble-size variation in the computations are considered. Comparisons of numerical results based on the model with both experimental measurements and results available in the literature have been performed. The results indicate that the developed numerical model accurately predicts the hydrogen production process. The study shows also that the best production process is reached by decreasing the main flow velocity. Increasing the current density and reducing the gap distance between the cathode and the anode of the electrochemical cell helps improving the hydrogen production process. The bubble-diameter formulation of the dispersed hydrogen gas considerably influences the local and global characteristics of two-phase stream. (C) 2015 Elsevier Ltd. All rights reserved.