INVESTIGATION OF NATURAL-CONVECTION IN CONVERGENT VERTICAL CHANNELS

Using air as the working fluid, natural convection heat transfer in a uniform wall temperature convergent vertical channel has been investig ated numerically. The investigation encompassed half angles of converg ence between 0 degrees (parallel-walled channel) and 10 degrees and th e solutions were performed for (S/L) Ra-s range of 1 to 2 X 10(4). In order to find a correlation format which will merge the convergent cha nnel results for low Rayleigh number ranges (Ra' < 10(2)) with those f or the parallel-walled channel ones, the minimum (S-min), mean (S-avg) , and maximum (S-max) interval spacing between channel walls were used as characteristic dimensions. It was found that merging was best achi eved by the use of maximum interval spacing (S-max) as the characteris tic dimension. These numerical findings agree with those for high Rayl eigh number ranges (Ra' > 10(2)) reported in the literature.