Heat transfer enhancement of nanofluid in metal foams

Metal foams are suitable for integrating and compacting heat exchangers and heat sinks for combining excellent mechanics, acoustics, electromagnetism and heat transfer performances as one. This paper presents the numerical study on the dual heat transfer enhancement effect of nanofluid flowing through metal foams based on the local thermal non-equilibrium model. The effects of foam morphology parameters and volume fraction of nanoparticles on corresponding flow and heat transfer are analyzed. The effects of quadratic term, thermal dispersion and local thermal non-equilibrium for the water-based nanofluid flowing in metal foams and different models for heat transfer enhancement analysis are compared with each other. Heat transfer is enhanced with a decrease in porosity or an increase in pore density and the existence of nanoparticles makes the pressure drop and heat transfer performance both increase. For water with nanoparticles, the inertial effect and the dispersion effect of convection in metal foams are obvious in the condition of large velocity. The local thermal non-equilibrium characteristic is obvious when the solid thermal conductivity is relatively large.