Abstract
Forced convective heat transfer experiment is carried out with a 5 × 5 rod bundle, which consists of square-arranged heating rods and multiple axially spaced grids. Deionized water is used to cool the heating rods, and the experiment is carried out under single-phase conditions with Reynolds number up to 28825 and 35185. The heat transfer coefficient downstream of a split-vane pair grid with blockage ratio of 0.51 is measured. The heat transfer enhancement effect downstream of this split-vane pair grid is significant, with the maximum heat transfer enhancement factor up to 1.52 and 1.46 at Re = 28760 and Re = 35190, respectively, and decay to 1.0 until X/Dh up to 20.5 approximately. The experimental data is compared with several heat transfer enhancement correlations, Yao et al.’s correlation and Miller et al.’s correlation have large deviations from the experimental data, while Holloway et al.’s correlation is in good agreement with the experimental data, and the relative deviation is within −3%∼7%, which is within the fitting error of ±8% of the correlation itself. The maximum heat transfer enhancement factor downstream of the grid has difference under different Reynolds numbers, more test data under various Reynolds number should be collected to verify whether the heat transfer enhancement is correlate with Reynolds number.
