TED-AJ03-108 AN ANALYTICAL STUDY OF ELECTROHYDRODYNAMIC INDUCTION PUMPING OF LIQUID FILM IN AN ANNULAR CONFIGURATION
スポンサーリンク
概要
- 論文の詳細を見る
Electrohydrodynamic (EHD) induction pumping is based on charges induced in a fluid due to the gradient of the electric conductivity. Such a gradient will always exist at the liquid/vapor interface. Consequently, charge dissociation will take place, and an equal number of positive and negative charges, resulting in a net charge of zero, will be generated. On applying an electric field, these charges will be attracted to locations exhibiting opposite polarity, or they will be repelled from locations with like polarity. An electric traveling wave, generated at the electrodes mounted along the flow passage, must be present for a net fluid motion to take place. In general, if the fluid is more conductive away from the electrodes, charges are attracted to the electrodes with opposite polarity. While the charges move toward the electrode, the electrode will pass on its polarity to the neighboring electrode, thus causing the charges to continuously lag the electric wave established at the electrodes. In this case, EHD induction pump is said to operate in the attraction mode. On the other hand, if the fluid is more conductive in the immediate vicinity of the electrodes, charges will be repelled from the electrodes with the same polarity. Therefore, the pumping direction would be opposite to that of the electric traveling wave. In this case, the EHD induction pump is operating in the repulsion mode. EHD induction pumping is non-mechanical, lightweight, and involves on moving parts. EHD induction pumps are not prone to mechanical failure or vibration, and the electric power input is generally negligible. They have great potential for more than just pure pumping applications. Enhancing heat transfer in the condensation process is one of the practical applications. Analytical solution for the EHD induction pumping of liquid film in an annular liquid/vapor configuration is presented. The geometry under consideration is that of fully developed pipe flow in an annular regime. Three sets of boundary conditions representing three different electrode configurations are considered. Two of the boundary conditions producing attraction pumping, and one results in repulsion pumping. Nondimensional parameters accounting for the applied voltage, fluid properties, and geometry are introduced. Results for the nondimensional interfacial velocity as a function of the controlling parameters are provided. In the analytical soutions presented, the ratio between the total radius of the tube and the wavelength is varied from 0.1 to 1,with the total radius varying from 0.005 m to 0.015 m. The liquid film thickness is varied from 1% to 10% of the total radius, which corresponds to the expected range of a thin film in an annular regime. Nondimensional electric wave angular frequency, electric conductivity, and dielectric constant are also varied over a wide range, and their effects on the interfacial velocity are presented.
- 一般社団法人日本機械学会の論文
著者
-
Aldini Salem
Department Of Mechanical Engineering Texas A & M University
-
Seyed Yagoobi
Department of Mechanical, Material, and Aerospace Engineering Illinois Institute of Technology
-
Seyed Yagoobi
Department Of Mechanical Material And Aerospace Engineering Illinois Institute Of Technology