The primary objective of the proposed research is to examine fast (high Reynolds number) flows in porous media. A unified approach is proposed, which integrates three research elements (1) upscaling theory (the method of volume-averaging ) with closure, (2) direct numerical simulation (DNS) of flow in porous media, and (3) PIV experimental studies of flows in porous media. The study will cover a broad range of Reynolds numbers [Re ~O(100-4000)]. The overall goal of this work is to provide a cohesive theory (with extensive experimental validation) to describe rather high velocity flows in a packed bed in a way that is consistent with the widely-used empirical expression known as the Darcy-Ergun-Forchheimer equation.
The wide range of applications of high Re flows in porous media includes gas adsorption, filtration, catalyst reactions, combustion, heat transport and other processes in fixed bed reactors, nuclear reactors and subsurface groundwater remediation. Due to the complex and irregular flow geometry within the pore space, the confining aspects of the flow, and the variable length scales, it is difficult to properly define the mean flow structure and associated turbulence of high Re flows in porous materials. These same complexities make experimental observations and numerical simulations extremely difficult. To date there exist few detailed PIV or DNS data for turbulent flows in randomly packed porous media, and none that cross validate among DNS and experiment. The proposed research brings together unique and complementary expertise and capabilities in experimental, computational, and theoretical approaches. Combined experiments and simulation data will be used to enhance our understanding of the flow physics in porous materials. The upscaling approach, which will focus on providing a consistent theory, has the potential to transform modeling approaches for heat or scalar transport in densely packed porous media. The experiments will involve pore-scale velocity field data for both simple cubic packing and randomly packed porous beads using three-component time-resolved particle image velocimetry. The DNS work will focus on high-fidelity, fully resolved direct numerical simulations of steady/unsteady inertial, transitional and turbulent flows. The detailed data from both sources will elucidate the complex flow structures and turbulence characteristics needed to form a theoretical basis for the development of a predictive tool for macroscopic flow and transport properties in porous media. Specifically, the data will facilitate direct evaluation of non-linear, closure terms due to unresolved, sub-grid scales of motion in the model.
The research plan will become the basis for training students and helping them appreciate the need for the integrated analysis necessary for complex problems. The PIs have a track record of involving underrepresented groups in their laboratories, both graduate and undergraduates (such as Textronic Scholars [available to first-year women] and University Honors Students. This project will reach out to developing engineers to provide a learning opportunity through the OSU-SMILE mentoring program for middle school students (which targets underrepresented groups). International exposure through collaborations with Insitut de Mecanique des Fluides de Toulouse will also be available to students. In addition the graduate students will be supported through the proposed grant and departmental funds to present their work at international and national conferences. The investigators will plan two special sessions at international conferences (such as AGU) during the final year.
This project is jointly funded by the Fluid Dynamics and Particulate and Multiphase Processes Programs in Chemical, Bioengineering, Environmental, and Transport Systems Division.
