Predicted flow characteristics of a wire-nonparallel plate type electrohydrodynamic gas pump using the Finite Element Method

• An analogy was found between the EHD pump and real voltage source.
• The maximum velocity of the pump varies linearly with the applied voltage.
• The maximum pressure difference is a square function of the applied voltage.
• We found heavier ions with smaller mobility increase the system efficiency.
• Optimum wall angle of the pump was found around 4° of orientation.

The aim of this paper is to numerically investigate the interaction between the electrostatic field and the fluid flow in a wire-nonparallel plate configuration of electrodes. The governing equations: Poisson equation for electric field, continuity equation for charge transport and the momentum equation for gas flow were solved using the Finite Element Method assuming a highly non-uniform mesh distribution. The main outcome of this study is the determination of velocity versus pressure characteristics of the pump, which provides useful information for predicting the pump performance and for control purposes. In addition, the efficiency and optimum geometric configuration are evaluated using this model. The numerical results show that a higher voltage leads to larger velocity and higher pressure, where the gas velocity is a linear, but pressure is a non-linear function of the supplied voltage. It was also found that there is an optimum wall angle for which the air volumetric flow rate from the outlet of the pump reaches the maximum value.