## 2 Materials and Methods
### Application of CFD Simulation Method  
The application process of CFD numerical simulation in this study primarily involves three stages: pre-processing, solving, and post-processing (Figure 4). During the pre-processing stage, the main tasks include defining the scope of the historical building numerical simulation, establishing simulation conditions, and creating geometric models. Additionally, it is crucial to determine the spatial dimensions of the computational domain, create the computational domain model, and conduct grid generation and grid independence verification according to the flow field simulation requirements. In the solving stage, geometric model files are imported into the solver, and solving parameters are set. These parameters include turbulent models, air state parameters, surface material parameters of the architectural geometric model, inlet and outlet conditions of the computational domain, and boundary conditions. This stage also involves defining the numerical format of the solver and controlling convergence iterations, ultimately leading to the generation of calculation solution files. The post-processing stage involves visualizing the numerical simulation results, presenting data such as contour plots, isosurfaces, streamlines, and particle trajectories, and assessing the distribution of the wind pressure and wind pressure coefficients on the surfaces of the historical building under various conditions.  
Numerical simulation methods for three-dimensional turbulence are typically classified into direct numerical simulation (DNS) and indirect numerical simulation [19]. DNS involves solving the entire range of turbulence scales directly using the Navier-Stokes equation. This approach is the most accurate but is computationally intensive and impractical for high Reynolds number flows around buildings. Indirect numerical simulation includes Reynolds-averaged turbulence models and Large Eddy Simulation (LES) turbulence models. Among these, Reynolds-averaged turbulence models, including the standard k-\(\varepsilon\) model originally applied in wind engineering research, are widely used. Variants like the RNG k-\(\varepsilon\) model and the Realizable k-\(\varepsilon\) model have been developed to improve predictions of separation zones and surface pressure distributions on bluff bodies [20]. In addition to the k-\(\varepsilon\) models, researchers have developed the standard k-\(\omega\) turbulence model, suitable for low Reynolds numbers and compressible shear flow. This model accurately predicts the confined flow around building walls and the free shear flow and performs well in near-wall regions, wake flows, and flow around obstacles [21]. The SST k-\(\omega\) model (Shear Stress Transport model) is an enhancement of the standard k-\(\omega\) model, incorporating  
Figure 4: The application process of CFD numerical simulation method.  
turbulent shear stress propagation. This modification enhances the model's accuracy and applicability in near-wall free flows. For analyzing the distribution of wind loads on the roofs and facades of historical buildings [22], this study focused on employing the SST k-\(\omega\) model due to its effectiveness in resolving complex flows around bluff bodies.