Abstract:

The flow in a solar chimney was dominated by natural convectionboundarylayer flow. Because of the restrictions of the operational parameters and thestructural parameters, the development of the boundary layer is different from freespace. The effects of temperature boundary layer thickness were discussed by direct numerical simulation. The results showed that the boundary layer thikness could meet with certain quantitative relations with    (y/Ra)^1/5 when the boundary layer can  freely develop and reach the steadystate stage, and the boundary layer thickness were relative to　w, Ra　when the boundary layer could not be freely carried out.

Key words: solar chimney; natural convection; direct numerical simulation; temperature boundarylayer