Theoretical and experimental study of electrohydrodynamic pumping through conduction phenomenon.

摘要

Electrohydrodynamic (EHD) pumping through conduction phenomenon is investigated experimentally and theoretically in this dissertation. For this purpose, a theoretical model for the pressure generation (i.e., without a fluid motion) based on the EHD conduction phenomenon is derived and dimensionless numerical solutions are obtained. Electric potential, electric field, charge density, and electric body force distributions for the selected electrode configuration are presented. The generated pressure as a function of the applied voltage is also presented. As an extended theoretical study, a theoretical model for the circulation of an isothermal fluid inside an enclosure is also derived. The numerical solutions are presented in dimensionless forms to illustrate the effects of the controlling parameters on the induced flow. The flow induced by EHD conduction phenomenon shows a great promise for various applications. For instance, the circulation/mixing by EHD conduction phenomenon can be used to enhance and/or to control the heat transfer. The numerical results presented here confirm the EHD conduction pumping concept theoretically.;The conduction pumping mechanism is also experimentally investigated using static pump (i.e. no net flow) apparatus with different electrode designs. Based on the theoretical understanding of the EHD conduction pumping mechanism, several electrode designs are designed and investigated. With these electrode configurations, sufficient pressure heads, on the order of 500 Pa per single electrode pair operated at 20 kV, are generated with very low electric power requirements making the EHD conduction pumping attractive to a number of applications in the presence and absence of gravity, such as capillary pumped loops and heat pipes. An EHD conduction pump is installed in the liquid return passage (isothermal liquid) from the condenser section to the evaporator section of a monogroove heat pipe to investigate the performance enhancement of the heat pipe. The augmentations of the heat transport capacity achieved by the EHD conduction pump at 10 kV are from 400 W to 600 W depending on the tilt, resulting in up to 300% enhancement. Furthermore, the EHD conduction pump provides immediate recovery from the dryout condition.