Akademik Veri Yönetim Sistemi
Heat Transfer Research, cilt.52, sa.9, ss.17-33, 2021 (SCI-Expanded)
© 2021 by Begell House, Inc.Forced convection heat transfer over surfaces of triangular and trapezoidal flat-plate collectors flush mounted on the roof of a residential house is investigated both experimentally and numerically for full-scale and 1:200 scale model collectors. Mass transfer experiments are performed by employing the naphthalene sublimation technique while numerical study is carried out using the ANSYS Fluent 17.0 software. The examined parameters are the roof tilt angle and the yaw angle of the house, Reynolds number, and the type of the collector. The results are given in terms of heat transfer parameters by employing the analogy between heat and mass transfer. It is seen that experimental and numerical results are in good agreement with each other in the Reynolds number range of the wind tunnel. The obtained results show that the heat transfer coefficient depends on the roof tilt angle and the yaw angle of the house, Reynolds number, and the type of the collector. It is seen that the heat transfer coefficient increases by changing the roof tilt angle from 25o to 45o and it also increases with increasing Reynolds number. In addition, the results exhibit that maximum heat loss occurs when the collector is in windward orientation. General expressions are given for windward and leeward orientations in the full-scale Reynolds number range. All the experimental and numerical results are correlated within an accuracy of ± 10% and ± 15%, respectively. It is seen that extrapolation of the results of 1:200 scale model to full scale gives incorrect results for full scale.