Nourdanesh N.,Heat and Fluid Flow Research Laboratory |
Esmaeilzadeh E.,Heat and Fluid Flow Research Laboratory
Applied Thermal Engineering | Year: 2013
Electrohydrodynamic conduction pumping of free surface dielectric liquid film, using flush electrodes, has been studied experimentally for various film temperatures. Volume flow rate, heat transfer and power consumption ratio and conduction pumping efficiency of free surface liquid film in different film thicknesses and temperatures have been investigated and then the best operating conditions have been presented. Also, the heat transfer coefficient on free surface liquid film passing on flush electrodes is compared with similar liquid film in absence of flush electrodes in different temperatures. Results show that as applied voltage increases, significant differences in volume flow rates have been observed by changing the temperature. Applied voltage related to the highest percentage of heat transfer coefficient enhancement demonstrates the reverse relation with temperature. Results confirm that there is a direct relationship between film thickness and the applied voltage related to the maximum heat transfer per pumps power consumption. © 2012 Elsevier Ltd. All rights reserved.
Tabatabaee-Hosseini P.,Heat and Fluid Flow Research Laboratory |
Sadri B.,Heat and Fluid Flow Research Laboratory |
Esmaeilzadeh E.,Heat and Fluid Flow Research Laboratory |
Esmaeilzadeh E.,Islamic Azad University at Tabriz
Experimental Thermal and Fluid Science | Year: 2012
This paper presents an experimental study on the liquid column behavior, resulted from impingement of two opposed inclined laminar jets in the presence of high voltage dc electric field. Electric field was generated through two stainless steel capillary nozzles which emit the opposed jets. Distilled water as working fluid of jets and transformer oil as stagnant medium were used in this study. Jets with a collision provide a liquid column which after a short distance its continuity disrupts and droplets is being made. By high speed imaging, the jet column breakup and droplets formation were investigated by observation of surface waves along the column. The effects of applied electric field on the column deviation, its breakup and droplets size formation were analyzed. Results show that increasing of droplets mean diameter and column deviation, but decreasing of droplet formation frequency was obtained by the electric field strength increment. Depend on the wave type on the column surface; twofold breakup behavior will be appearing when the active method of induced electric field of high voltage superimposed. © 2012 Elsevier Inc.