Heat transfer coefficient for asymmetric heated rectangular duct in transient state

Abstract

Test results are reported from the experimental results of a rectangular solar air heater operated under solar simulator in steady and unsteady state conditions. The data obtained are used to develop two regression models for the prediction of Nusselt number. For steady state conditions, the model NuD = 0.0088ReD0.88 is proposed for the prediction of the mean Nusselt number of the collector. In the transient state, the model NuD = 0.0064ReD0.85 exp (77.8 × FO) is proposed for the prediction of the mean Nusselt number. The first model agrees with the models cited in the literature whereas the second proposed model is not compared with any other model because similar models are not available in the literature.