| Popis: |
Results are reported here for an experimental investigation of the local heat transfer of water flowing through vertical circular tube of 15 mm inside diameter and 370mm length, packed with a spherical steal particles of diameter 3.2 and 1.07 mm. The tube is heated electrically with a constant heat flux on the wall. During this work Reynolds number was varied from 10 to 10000 and prandtl number was about 7. Results show that, in the laminar flow region the ratio of thermal entrance length to inner tube diameter is equal to 7, while in the turbulent flow region this ratio has a negligibly small value, which means that the mean and local heat transfer coefficients are equal in the turbulent region of packed bed tubes. In comparison with the available literature the present results show a quite good agreement. |
