Date of Award
Doctor of Philosophy
G. M. Colver
An investigation into the effect of electrically driven particles on the air flow in a rectangular duct at room temperature and near atmospheric pressure is reported. The experiments were carried out in both a closed volume and in a rectangular duct. For the closed volume, the vertical velocity of copper and glass particles for diameters of 37)m to 88)m at electric field strengths in the range of 0 to 8.125 kv/cm was determined using a Laser Doppler Anemometer. In the duct, the effect of the electrically driven (actually oscillating) particles on the air flow was investigated;The pressure drop, particle vertical and horizontal velocities were measured along the duct for copper and glass particles having diameters of 63-74 and 74-88)m and 44-63, 63-74 and 74-88)m respectively at electric field strength of 5 kv/cm. The particle vertical and horizontal velocities were measured by a Laser Doppler Anemometer. The pressure drop along the duct was found, using a precision pressure sensor. Results of this test were analyzed for the pressure gradient per unit mass flow rate of the solid particles, friction factor per unit mass flow rate of solid particles, and the apparent drag coefficient of multiple particles. Correlations of the apparent drag coefficient as a function of a modified particle Reynolds number were obtained for copper and glass particles. The particle Reynolds number ranged from 6 to 32 while the hydraulic Reynolds number ranged from 1300 to 12551 for these correlations;The effect of both electric field strength and particles mass flow rate on the flow pressure drop were also measured;The particle to air velocity ratio, the saltation velocity, and the pressure drop were calculated. Comparison with the measured values shows good agreement;The present work verifies the concept of using the electric augmentation technique in particle conveying as a tool for measuring multiple particle drag coefficient and also as a means of optimizing particle transport for minimum pumping losses.
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/
Ahmed Mohie El-Din Saad Sarhan
Sarhan, Ahmed Mohie El-Din Saad, "Effect of electrically driven particles on air flow in a rectangular duct " (1989). Retrospective Theses and Dissertations. 9175.