*3.2. Simulation Results and Error Analysis*

In the correlation test (Figure 7), the two data sets showed a high correlation (R2 = 0.82, 0.77). In the paired *t*-test (Table 3), the data significance (P) was greater than 0.05 for both groups at 95% confidence, which means that there was no significant difference before and after the simulation.

As a result, the CFD numerical model developed can predict the neighborhoods' PM2.5 concentration and wind environment more accurately. It can be used to predict a neighborhoods' PM2.5 concentration and wind environment under different morphological parameters.

**Figure 7.** Correlation test before and after simulation of: (**a**) Neighborhood A; (**b**) Neighborhood B.


**Table 3.** P1 and P2 simulated data were paired with measured data for the sample test.
