Computation of electrohydrodynamic ion drag direct current pump flows for wing plasma actuation using a semi-numerical technique

Plasma actuation in aircraft wing aerodynamics has been shown to achieve enhanced flow control. This enables an improvement in aerodynamic efficiency, stability and control and can successfully accelerate, decelerate or divert air flows to reduce aerodynamic drag, fuel consumption and even CO2 emissions by up to 25%. Both AC and DC power sources can be used to achieve plasma flow control, in addition to microwave sources. The design of robust plasma pump supply devices is critical to sustaining the induced body force by a strong electric field and the generation of heat during an electric arc. These devices feature ion drag characteristics and require electrohydrodynamic models for their simulation. The most promising plasma actuator designs feature glow discharge plasma actuators which were pioneered by Dr. J. Reece Roth of the University of Tennessee, USA. These can produce sufficient quantities of glow discharge plasma in the atmosphere pressure air which maximizes airflow control performance. Motivated by probing deeper into the fluid dynamics of plasma actuator electrohydrodynamic ion drag pumps (based on DC power), in this presentation we describe a recent semi-computational analysis of viscous EHD pumping in a cylindrical ion drag pump. The optimized DTM-Pade method, a combination of the Zhou electrical circuit differential transforms method (DTM) and analytical Pade approximants (power series expansions), is applied to provide highly accurate, stable and fast semi-numerical solutions for the regime considered. Verification of solutions with MATLAB numerical quadrature is included. The influence of electrical Reynolds number (ReE), electrical slip number (Esl) and electrical source number (Es) on charge density (*), electrical field (E*) and electrical potential ( *  ) and ion drag pump power efficiency ( EHD  ) is scrutinized. Electrical potential is substantially enhanced with an increase in electrical slip effect i.e. with exacerbation in relative motion of the injected charges with regard to the bulk fluid velocity. Elevation in electrical Reynolds number (which simulates the relative significance of the charge convection effect and defined as the ratio of the timescales of charge convection by flow to that of charge relaxation by Ohmic conduction) induces a minor enhancement in efficiency whereas a marked reduction is generated in efficiency with increasing electrical source numbers. Furthermore, a strong suppression in charge density is induced with an increase in electrical slip number. The computations provide a useful benchmark for further extension to more complex geometrical configurations with ANSYS FLUENT commercial CFD software (Multiphysics solver) and indeed experimental tests.