Measurements of Transitional and Turbulent Flow in a Randomly Packed Bed of Spheres with Particle Image Velocimetry

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• 作者：Shervin Khayamyan ; T. Staffan Lundström…
• 关键词：Porous media ; Randomly packed bed ; 2D ; PIV ; Refractive index matched (RIM ) ; Velocity statistics ; Laminar and turbulent flow and recirculation zones
• 刊名：Transport in Porous Media
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：116
• 期：1
• 页码：413-431
• 全文大小：4611KB
• 刊物类别：Earth and Environmental Science
• 刊物主题：Geotechnical Engineering & Applied Earth Sciences; Industrial Chemistry/Chemical Engineering; Hydrology/Water Resources; Civil Engineering; Hydrogeology; Classical and Continuum Physics;
• 出版者：Springer Netherlands
• ISSN：1573-1634
• 卷排序：116

文摘

Particle image velocimetry (PIV) has been used to investigate transitional and turbulent flow in a randomly packed bed of mono-sized transparent spheres at particle Reynolds number, \(20<{{ Re}}_{\mathrm{p}}< 3220\). The refractive index of the liquid is matched with the spheres to provide optical access to the flow within the bed without distortions. Integrated pressure drop data yield that Darcy law is valid at \({{ Re}}_{\mathrm{p}} \approx 80\). The PIV measurements show that the velocity fluctuations increase and that the time-averaged velocity distribution start to change at lower \({{ Re}}_{\mathrm{p}}\). The probability for relatively low and high velocities decreases with \({{ Re}}_{\mathrm{p}}\) and recirculation zones that appear in inertia dominated flows are suppressed by the turbulent flow at higher \({{ Re}}_{\mathrm{p}}\). Hence there is a maximum of recirculation at about \({{ Re}}_{\mathrm{p}} \approx 400\). Finally, statistical analysis of the spatial distribution of time-averaged velocities shows that the velocity distribution is clearly and weakly self-similar with respect to \({{ Re}}_{\mathrm{p}}\) for turbulent and laminar flow, respectively.