Effect of Lewis Number on Unsteady Double Diffusive Buoyancy Induced Flow in a Triangular Solar Collector with Corrugated Wall

A numerical investigation has been carried out in this paper to study the effect of varying Lewis number on the nature of heat and mass transfer in a triangular solar collector at unsteady condition. The triangular solar collector consists of two inclined glass covers and an absorber plate. The situation studied here resembles heat transfer phenomena in solar collectors and hence a thorough study on the effect of different parameters dictating this kind of heat transfer is essential. Bottom corrugated wall is subjected to high temperature and high concentration. Finite element method was employed to solve the unsteady dimensionless governing equations of continuity, momentum, energy and concentration of the problem. Calculations were carried out for Raleigh number ranging from 104 to 106 and for dimensionless time parameter = 0.1, 0.5 and 1. For the conditions mentioned here the effect of varying local and overall Nusselt and Sherwood number at those conditions are discussed. A comprehensive explanation follows each result.