Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7054719 | International Journal of Heat and Mass Transfer | 2018 | 11 Pages |
Abstract
Experiments have been carried out to investigate the heat transfer downstream of spacer grids in a vertical 5â¯Ãâ¯5 rod bundle cooled by single phase water. Wide ranges of mass flow rate (Re from 2000 to 30,000) and heating power (25-150â¯kW/m2) are examined. Buoyancy force as a prominent factor to influence the development of heat transfer downstream of spacers is observed for the first time. For small buoyancy affected conditions, the heat transfer downstream of spacers decay exponentially to the fully developed values, while for highly buoyancy effect conditions, the heat transfer development downstream of spacers shows complicate behaviors. An explanation of the effect of buoyancy force on heat transfer downstream of spacers is addressed. Existing correlations perform unfavorable predictions with current experiments because of the ignorance of buoyancy effect. Based on the current experimental data, a new correlation accounts for the buoyancy effect has been proposed and shows good predictions.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
Fluid Flow and Transfer Processes
Authors
Da Liu, Hanyang Gu,