Airside Performance of Staggered Tube Bundle Having Shallow Tube Rows

Abstract

Clum. Ens. C m . . 2Rll. Val. 187. pp. 129-147 Rcprinu available dinrrly from the publisher Photocopying pcrmittd by license only Q 2001 OPA (Ovcrwrr Publirhcrl A m i s t i o n ) N.V. Published by lianse undcr the Gordon and B m c h Scicnoc Publirhcn imprint.Airside performance for tube bank having N= 1-6 are reported in this study. Test results indicated that the heat transfer coefficients for N = l and N = 2 are comparable and the heat transfer coefficients increase with the number of tube row. For the same P,, PI, the heat transfer coefficients for the tube bank containing smaller diameter tube are higher than those of larger tube diameter for N 2 2 and is comparable for N= I. Comparisons of the heat transfer performance were made with several correlations. It is found that the Gnielinski correlation gives the besl predictive ability. For multiple-row heat exchangers, the predictive ability of the well-known Zukauskas correlation is also good. But the correlation under-estimate the present I-row heat exchangers. As a consequence, a slight modification to the iukauskas correlation is proposed that can extend its applicability in N= l and R~D < 1000. In addition, modification to the frictional performance of iukauskas correlation is also made. The mean deviation of the proposed frictional correlation is 11.2%.

Thermo-hydraulic study of a single row heat exchanger consisting of metal foam covered round tubes

“…As can be seen, and this was also noted by Wang et al [49], the Zukauskas and Ulinskas [50] correlation underestimates the pressure drop. Wang et al [49] presented a correction factor, but this factor was found to show very erratic variations in the considered range of , so it was not used.…”

“…Wang et al [49] presented a correction factor, but this factor was found to show very erratic variations in the considered range of , so it was not used. The good agreement between the experimental data and the predictions for = 3.57 (Fig 4B) should be considered coincidental, as the correlation is only valid for .…”

Wake behind a rough (metal foam-covered) cylinder in cross-flow

“…The results could be extrapolated to cover the lower pitch value but this would not help too much as the other two experimental sources tend to disagree within the range of pitch values considered therein. Overall, our results seem to be closer to those of T'Joen et al [186] at least for the reported data-points in that work. …”

“…As another attempt to verify our numerical predictions, Figure 71 is presented to compare our simulation results (averaged over all velocities) for pressure drop with those available in the literature for single row banks of tubes. Interestingly, our results for the widest pitch considered here perfectly agree with experimental data from [186,187]; but the densest case considered in our work has not been investigated in the aforementioned papers. The results could be extrapolated to cover the lower pitch value but this would not help too much as the other two experimental sources tend to disagree within the range of pitch values considered therein.…”

“…Where appropriate I have obtained copyright permission from the copyright holder to reproduce material in this thesis. : CD results of this study compared to T'Joen et al [185] and Wang et al [186] ... 174 …”