PRESSURE DROP IN HIGH DENSITY POROUS METAL VIA TOMOGRAPHY DATASETS

Abstract

ABSTRACT

There is little or no published articles on Computational Fluid Dynamics (CFD) approach to study the contributory effect of sudden change in pore- volume on the flow behaviour of high density porous structures using CFD approach coupled with 3D advanced imaging techniques. This study combines three-dimensional advanced imaging techniques and computational fluid dynamic modelling and simulation (CFD) to characterise the pressure drop of flowing fluid across high-density porous metals utilising high-resolution X-ray computed tomography datasets. The modelling approach quantifies the combined effects of pore volume fraction (80 to 95%), pore connectivity, pore size (0.2 to 5.0 mm) and morphology on the flow behaviour of porous metals and to study in more detail the pressure drop behaviour characterised by the sudden change in pore volume by stacking of differential porous samples at the pore-level. Numerically, the pressure drop at velocity 1m.s-1 of Inc 450µm and Inc 12000µm are 112.48 pa and 14.52 pa respectively and after stacking the both samples the pressure drop at same velocity is 72.57 pa. The resulting predicted values of the pressure drop as a function of superficial fluid velocity ranging from Darcy to Turbulent fluid flow regimes were used to account for the permeability (k0) and Form drag coefficient (C) of these materials. From literature the measured values of permeability and Form drag coefficient for the 20mm thick Inc 450µm sample are 1.69 ± 0.03x10-09 m2 and 8566.4 ± 150 m-1 respectively while the CFD computed values of the permeability and Form drag coefficient for this range of superficial fluid velocities are 1.60x10-09 m2 and 8530.8m-1respectively. Supportable agreement between CFD modelled data against empirical measurements available in the literature was substantiated. Therefore it is considered that this approach could lead practically to minimizing the number of design iterations required for the processing of novel-attributing porous metallic materials for applications involving fluid flow.