Stability of electrohydrodynamic induction pumping of a stratified liquid/vapor medium in the presence of an external load

A stability analysis of electrohydrodynamic induction pumping of a stratified liquid/vapor medium incorporating an external load is carried out in nondimensional form. General stability criteria are introduced for attraction and repulsion mode pumping. Stability is found to depend on dimensionless geometric parameters of the pump as well as dimensionless electric parameters of the working fluid. The criteria are investigated in detail, considering two specific cases each of attraction and repulsion mode pumping. Parameter maps are presented indicating regions of stable and unstable operation for each case. Finally, the effect of the dimensionless electric wave angular velocity on the dimensionless interfacial velocity is studied for selected stable and unstable cases. It is shown that unstable pumps can be stabilized through careful selection of the involved parameters and that the overall performance of the pump is likely to be improved in the process.