INVESTIGATION OF NATURAL CONVECTION IN CONVERGENT VERTICAL CHANNELS

摘要

Using air as the working fluid, natural convection heat transfer in a uniform wall temperature convergent vertical channel has been investigated numerically. The investigation encompassed half angles of convergence between 0° (parallel-walled channel) and 10° and the 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 channel results for low Rayleigh number ranges (Ra' < 10~2) with those for 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 achieved by the use of maximum interval spacing (S_(max)) as the characteristic dimension. These numerical findings agree with those for high Rayleigh number ranges (Ra' > 10~2) reported in the literature.