Varying Gravity Force Using Magnetic-Field Emulated Artificial Gravity: Application to Cocurrent Gas−Liquid Flows in Porous Media

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• 作者：F. Larachi ; M. C. Munteanu
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2010
• 出版时间：April 21, 2010
• 年：2010
• 卷：49
• 期：8
• 页码：3623-3633
• 全文大小：445K
• 年卷期：v.49,no.8(April 21, 2010)
• ISSN：1520-5045

文摘

A method was proposed to investigate the effects of modifying, via magnetic fields, both modules and directions of the net gravitational body forces of gas and liquid and to follow their incidence on the evolution of pressure drop, wetting efficiency, and liquid holdup in cocurrent gas−liquid downflow and upflow fixed beds. New pseudogravity cases arose and were rationalized in terms of driving or resisting forces in two-phase flows. The method was based on applying on nonmagnetic (paramagnetic and diamagnetic) fluids strong static inhomogeneous magnetic fields generated in the vertical atmospheric bore of a superconducting magnet. Depending on the signs of the magnetic susceptibility and of the gradient of magnetic induction, the gas or liquid was subjected to macrogravity, microgravity, and retrogravity. Gas and liquid in microgravity, gas in macrogravity and liquid in microgravity, gas in retrogravity and liquid in macrogravity, and gas and liquid in retrogravity were the combinations studied. The variations of pressure drop, liquid holdup, and wetting efficiency were rationalized by distinguishing the conditions whereby the total apparent fluids’ weight under the magnetic field was either acting as a driving or as a resisting force. Liquid holdups in cocurrent downflow were found to decrease in retrogravity and increase in microgravity and macrogravity, whereas in upflow liquid holdups increased regardless of the prevailing artificial gravity.