A numerical and experimental investigation of heat transfer issues in the practical utilization of unglazed, transpired solar air heaters

In the study of unglazed, transpired solar collectors researchers have not addressed the problems of low-conductivity flat plate performance or the determination of wind heat loss from corrugated plates. Applications exist for low-conductivity flat plates, and convective heat loss from corrugated plates is a significant fraction of the incident radiation for small installations. This dissertation addresses these two issues by using numerical and experimental approaches. The numerical work consists of modelling the flow conditions and plate geometries with the FLUENT computational fluid dynamics software to aid in experimental design and flow and heat transfer visualization and to obtain results outside the bounds of the experimental domain. The experimental work utilizes the laboratory apparatus at the National Renewable Energy Laboratory to determine the low-conductivity flat plate performance relative to high-conductivity flat plates and to measure the heat loss from the downstream edge of corrugated plates. The results of the work are correlations for the heat transfer performance of low-conductivity flat plates and for the wind heat loss from corrugated plates, in addition to extending the understanding of the physical mechanisms affecting the plates' behavior.