Experimental hydrodynamic study of flow through metallic foams: Flow regime transitions and surface roughness influence

• The influence of the surface roughness is studying, where, the pressure drop increase from the small sample to the rough one.
• The present results are compared to those available in the literature for porous media and metallic foam.
• The flow-regime transitions from pre-Darcy to Turbulent are identified for each metallic foam sample.
• The metallic foam can exhibit a different permeability and Forchheimer coefficient in each fluid regime type.

The aim of the present work is to study the hydrodynamic behavior of the single phase water flow through three metallic foam samples (i.e. Copper, NiFeAlC, and Inconel) in a plate heat exchanger. These samples have a same pore diameter (1200 µm) and grade (20 PPI), however, the Microscopic images show that the ligament diameter and the surface roughness are different. The effect of the metallic foam surface roughness and the ligament diameter on the pressure drop behavior is analyzed, and the regime transitions from pre-Darcy to turbulent are identified. It is found that more, the metallic foam surface is rough, more the pressure drop is important and the turbulent regime is reached rapidly. The Permeability and Forchheimer parameters were calculated for each flow regime. It is noticed that each fluid regime can exhibit different permeability and Forchheimer coefficient for the same foam sample. The present data were confronted to those available in the literature and a good qualitative and quantitative agreement was obtained.