Numerical study on natural convection inside the channel between the flat-plate cover and sine-wave absorber of a cross-corrugated solar air heater

摘要

A numerical study has been counducted to investigate the natural convection inside the channel between the flat-plate cover and the sine-wave absorber in a cross-currugated solar air heater. The effects of major system parameters on the natural convection ehat transfer are simulated. These parameters include ΔT, the difference of averge temepratures between the cover and the absorber, A, the characteristic height ratio of the channel which is defined as the ratio of the channgel height to the amplitude height of the wavelke absorber, L, the characteristic geometric ratio which is defined as the ratio of one-fourth of the waveleenth to the amplitude height of the absorber, and θ, the angle of incination of the heater. The numerical results show that to suppress the natural convection heat loss effectively, A should be larger than 2, L larger than 1 and θ less than 40 deg.