## 5 Result Analysis
### Case 2  
In Case 2, the applied loads were applied symmetrically along the rows, as shown in Figure 4b. The boundary conditions set for the simulations performed in this studies are as follows: at the end  
Figure 8: The results of the field of temperature in the \(x\)–\(y\) plane through planes: (a) \(z_{adm}=0\); (b) \(z_{adm}=0.244\); (c) \(z_{adm}=0.489\); and (d) \(z_{adm}=1\).  
of the rows of the server racks, 50% of the maximum thermal load was applied, while 70% of the maximum thermal load and 90% of the central racks were applied: \(q_{adm}=0.460\) (50%), 0.676 (70%) and 0.892 (90%), respectively. The minimum air flow dimensionless velocity was set as follows: \(v_{adm}=0\). The results from the simulations of the temperature field can be seen, respectively, in Figures 9 and 10 for the \(y\) and \(z\) planes.  
Figures 9 and 10 show the temperature field predictions for the case study. The temperature fields are presented with the same planes as in Case 1.  
By observing Figure 9, the probability of hot spots on the server racks can be accurately assessed. In the plans of Figure 9, it can also be easily noticed that the average of the non-dimensional temperature values in the extraction zone exceeds \(T_{adm}=0.125\). Therefore, the minimum air flow dimensionless velocity is not sufficient to successfully cool all the racks and, thus, avoid the occurrence of any type of hotspots.  
By analyzing Figure 10, it can be seen that a few server racks can reach temperatures that exceed the minimum limit considered for a hot spot. In the extraction zone, the mean value of the dimensionless temperature in this zone is expected to exceed \(T_{adm}=0.125\) (the hot spot for this area), which means that hot spots in the extraction zone are very likely to occur.  
In the case of the maximum level of air flow dimensionless velocity, \(v_{adm}=1\), the results from the simulations of the temperature field can be seen, respectively, in Figures 11 and 12 for the \(y\) and \(z\) planes.  
Figure 11: The results of the field of temperature in the \(x\)–\(z\) plane through the planes: (**a**) \(y_{adm}=0.100\); (**b**) \(y_{adm}=0.485\); and (**c**) \(y_{adm}=0.900\).  
Figure 10: The results of the field of temperature in the \(x\)–\(y\) plane through the planes: (**a**) \(z_{adm}=0\); (**b**) \(z_{adm}=0.244\); (**c**) \(z_{adm}=0.489\); and (**d**) \(z_{adm}=1\).  
As shown in Figure 11b, the predicted dimensionless temperature does not exceed \(T_{adm}\) = 0.150. The zone that can reach this temperature is very small and very close to the base. In the other planes, the dimensionless temperature does not exceed \(T_{adm}\) = 0.200, which is also only reached at or near the base of the server racks.  
Due to the increase in inlet air flow velocity, the temperature fields shown in Figure 12 predict that the average temperature in the data center room is similar to the inlet air temperature and that the formation of hot spots is almost non-existent, since the predicted maximum dimensionless temperature is \(T_{adm}\) = 0.250. As mentioned for Case 1, the hot spots can be easily spotted by noticing the colors related to the values, which are higher than the dimensionless temperature, \(T_{adm}\) = 0.350. In addition, no hot spots are expected in the extraction zone.