Flow visualization study of partially filled channel with aluminium foam block

This experimental study investigated fluid dynamics of a channel partially filled with a metal foam block with various pore densities; 5, 10 and 30 PPI. The effects of foam heights, in a range of 0.004 – 0.050 m, and inlet velocities, from 3.9 to 12.5 m/s, on the flow field were investigated using Particle Image Velocimetry (PIV). For a more comprehensive analysis of the problem, detailed flow patterns inside the porous foam were visualized by applying a thermal imaging method. Results show that there are different flow behaviours in the partially filled channel depending on the key parameters. A boundary layer is formed on the horizontal fluid/foam interface, which is much more noticeable and thicker in high blockage ratio cases. The low-pore density foam allows the flow to pass through its porous structure while the higher pore density foam imposes more restrictions on the flow pushing the fluid away from the foam into non-porous region on the top of the foam block before reaching the foam end