Numerical investigation of forced convection heat transfer from outer surface of the roof of a house used as a flat plate solar collector

This study presents the results of forced convective heat transfer coefficients on the surface of flat-plate solar collectors flush mounted on two-story residential buildings and exposed to the wind. This study was carried out numerically. In this period it was used fluent package program.In this numerical study, houses having square and rectangular shaped collectors were used in order to determine the average heat transfer coefficient. Solutions were performed for various collectors having ?=25º and 45º roof slope angles and ß=0º, 90º, and 180º wind attack angles. These models were created using Gambit 2.0 package program and meshes were built on these models. Air was used as the working fluid. Governing equations were solved for steady-state, three dimensions, and turbulent flow conditions. k-? realizable model was used as the turbulence model. Correlations having forms of Nu= a x Reb were obtained.It has been found that the average transfer coefficient is remarkably sensitive to the wind direction and the roof slope angle. Comparison of computational results with experimental results showed satisfactory agreement.It was observed that the currently standard computational equation ( , which is, in reality, not well suited to the application) estimates the average heat transfer coefficient low.