Numerical Analysis of Compound heat transfer enhancement by single and two-phase models in parabolic through solar receiver.

A three dimensional numerical investigation of turbulent forced convection of Alumina/dowtherm-A nanofluid inside a non-uniformly heated parabolic trough solar collector receiver equipped by two longitudinal fins for improving heat transfer by single and two-phase modeling has been carried out. The heat flux around the absorber tube was obtained applying Monte Carlo ray trace technique. The numerical results were validating with the empirical correlations existing in literatures and good agreement was obtained. The calculated results demonstrate that two-phase models predict a higher convective heat transfer coefficient however the predictions of Darcy friction factor by single and two-phase approaches are essentially the same. Two-phase mixture model has been used to investigate the influence of nanoparticles mean diameter on heat transfer phenomena; it found that a smaller nanoparticles increase better convective heat transfer.DOI: http://dx.doi.org/10.5755/j01.mech.23.1.14053