The purpose of this study was to obtain a correlation for a proposed solar concentrating collector element, which could be used for design of a large-scale collector. A mathematical model was developed to predict the velocity and temperature fields in a spirally grooved flow passage. The curvature produced a secondary flow and caused departures from the symmetric velocity profile. The analysis considered heat transfer in the developing and fully developed regions through the collector element. The experimental heat transfer values were compared with those values from the mathematical analysis. The numerical study of fully developed laminar flow in a spirally square groove gave satisfactory results for heat-transfer values in fully developed temperature field under the condition of uniform heat flux (on heated wall). The Nusselt number for a curved pipe flow was obtained as a function of Dean number De=Re(a/R)/sup (1/2)/. As the Dean number values increased, the heat-transfer coefficient and Nusselt number increased. The experimental study was carried out for water flow in a curved square groove. The outlet mean and wall temperatures were measured and the local Nusselt number values were obtained.
Relation:
中華民國力學學會第十四屆全國力學會議論文集(二)=Proceedings of the 14th National Conference on Theoretical and Applied Mechanics (II), pp.511-1519
