## 1 Introduction  
Previous research showed that high-rise buildings often have a significant impact on the airflow in their surrounding areas [1; 2; 3; 4; 5; 6; 7], which can be divided into high-wind-speed areas and low-wind-speed areas. High wind speeds can cause some damages, while low wind speeds cannot contribute to the decrease in air pollutants [8; 9; 10; 11]. Moreover, the wind environment around high-rise buildings can impact their energy consumption [12; 13]. Therefore, it is necessary and important to predict the wind environment around high-rise buildings before construction. In recent years, Computational Fluid Dynamics (CFD) has been increasingly used in predicting the wind environment, though the accuracy of the calculation results is still under research. Many scholars have verified the calculation accuracy of different turbulence models based on tetrahedral and hexahedral meshes under different conditions for high-rise buildings [14; 15; 16; 17; 18]. For instance, [PERSON] and [PERSON] compared the CFD simulation results with wind tunnel experiment results and found that the k-\(\epsilon\) model could predict velocity and pressure fields well under fine-mesh conditions [19]. [PERSON] and [PERSON] simulated the wind effects on a super high-rise TV tower and found that the Realizable K-Epsilon (RKE) model could come up with more accurate results in terms of mean pressure coefficients and streamlines than the Standard K-Epsilon (SKE) and RNG K-Epsilon models [20]. [PERSON] et al. presented two cases of wind flow around high-rise buildings and concluded that the RNG K-Epsilon model and the RKE model overpredicted the reattachment length behind the buildings [21]. Likewise, other scholars also pointed out the inaccuracy of using revised k-epsilon models in reproducing the weak-wind area and the reattachment length behind the building [22; 23; 24; 25].The Reynolds Stress Model (RSM) with modified inlet atmosphere boundary conditions, as proposed by [PERSON] et al., was able to better simulate the wind flow around high-rise buildings [26]. [PERSON] et al. compared the predicted results using revised K-Epsilon models and Large Eddy Simulation (LES) for a high-rise building and found that the LES showed better performance in predicting mean velocity distributions and turbulence energy distributions [27]. [PERSON] et al. also found that the LES model showed good performance in predicting the mean surface pressure of high-rise buildings [28; 29; 30]. [PERSON] et al. evaluated the influence of calculation parameters (e.g., mesh numbers, discretization time step and sampling time, etc.) on simulating the outdoor wind flow around an isolated high-rise building and found that the Detached Eddy Simulation (DES) made a similar prediction of the mean wind velocity field in the lateral side and wake region, while it had less computational cost than the LES [31]. To summarize, the LES model and the DNS model can be more accurate in predicting the airflow, but they require higher computational costs. A range of modified k-\(\epsilon\) models can be adopted as a fast solution for many engineering designs and predictions [32; 33]. Some scholars explored the accuracy of the CFD simulation results based on different structured mesh generation methods. [PERSON] et al. proposed the near-wall mesh generation method to simulate wind environments and evaluated the reliability of this method by comparing the CFD results with the wind tunnel experiment results. The near-wall mesh generation method could provide sufficient near-wall mesh density, while it could not lead to a significant increase in the total amount of meshes and the consequent computational cost [34]. In recent years, with the development of computational technology, the types of mesh calculations based on unstructured mesh generation approaches gradually increased. [PERSON] et al. assessed the wind pressure distribution and wind force coefficients on the facade of a high-rise building, using the combined model consisting of a Cartesian mesh and an unstructured mesh.