Experimental studies of convection flow and heat transfer in a horizontal divergent duct heated from a side which induces combined natural and forced convection have been carried out. For the purpose of comparison, a duct made of two vertical parallel plates with one of the plates heated uniformly and the opposite plate well insulated is also made. The divergent duct is formed in a similar channel by inclining the insulated vertical wall with respect to the heated vertical wall so as to create a divergent angle of 3° with a larger exit. The gap between the plates is small and the height to the gap ratio of the channel cross section is 6.67 at the entrance. Both flow visualization and the heat transfer along the heated wall are measured. The Reynolds number ranges from 316 to 1500, the buoyancy parameter, Gr / Re2 from 0 to 20000 and Pr of the airflow is 0.707. The effect of the Reynolds number and the buoyancy parameter on the heat transfer is presented and discussed. It is found that the small divergence of the duct can have a significant effect on both the flow and the local heat transfer. However, enhancement of the heat transfer can make the averaged Nusselt number approaches to the results of the parallel channel.
|Number of pages||9|
|Journal||International Journal of Thermal Sciences|
|Publication status||Published - 2009 Jan 1|
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics