Volume I - Section IV - Experimental Work and Verification of CFD Methodology 
Page IV - 105 
4.23.2.2 Populated Room 
For ease of comparison here, the experimental data are overlaid on top of the CFD results for this 
section of work. The experimental data are represented as contour lines, i.e., lines of the same 
value, while the CFD results are represented as fill plots. 
Speed Results 
The comparison between the experimental and CFD speed field results at 1.02m (40”) from the 
south wall are shown in figure 4.76. Note that the left side of the plot represents the east wall of 
the room, and the key range is between 0 and 40 fpm (0.2 m/s). The plot shows that, 
qualitatively, the CFD simulation predicts the plumes of air resulting from the heaters in the 
individual cages. However, the experimental data show several spots of high speed in the rest of 
the plot that cannot readily be explained. Further, the experimental data demonstrate a peak value 
of 0.86m/s (172 fpm) well away from the cage plumes, and other measurement points where the 
speed value is above 0.60m/s (120 fpm), whereas the CFD prediction shows more modest peaks. 
Moving further towards the North Wall, figure 4.77 shows the comparison at the plane 1.93m 
(76”) from the south wall. The experimental data again look a little uncertain. In particular, the 
high speeds in the lower right and left sides of the plot appear very similar to those in the 
previous plot. In this physical scenario, the room has very different boundary conditions near the 
north and south walls, and so these high spots appear unrealistic. Further, the peak experimental 
speed at this plane is 1.25m/s (250 fpm), with various other places showing values above 
l.OOm/s (200 fpm). Finally, the experimental data do not show any indication of the effect of the 
exhaust fan in the comer of the room. This feature is clearly evident in the CFD field. 
Temperature Results 
The comparisons between the experimental and CFD temperature field data at planes 0.71m, 
1.02m, 1.32m, 1.63m, 1.93m and 2.13m (28”, 40”, 52”, 64”, 76, and 84”) from the South Wall 
are shown in figures 4.78 to 4.83 respectively. Note that the left side of the plot represents the 
east wall of the room, and the key range is between 21.1 °C to 25.0 °C (70.0 and 77.0 °F). The 
planes represent comparisons close to the South Wall cage rack through to the North Wall door. 
The plots show that there is generally very good agreement between the experimental and CFD 
results at each of the planes. The CFD also correctly predicts many of the physical features 
exhibited by the experimental data, for example, the stratification of the air temperature shown 
most clearly in figure 4.82, and the diffuser airflow shown in figure 4.80. 
The percentage differences between the experimental and CFD results confirm the good 
agreement between the two sets of data, as indicated in Tables 4.2.15 to 4.2.20. In particular, the 
average difference at the 0.71m (28”) plane is 11.9 percent, at the 1.02m (40”) plane is 13.0 
percent, at the 1.32m (52”) plane is 18.7 percent, at the 1.63m (64”) plane is 1 1.9 percent, at the 
1.93m (76”) plane is 12.1 percent, and at the 2.13m (84”) plane is 18.5 percent These 
