## 4 Method Conceived for Comparison Based on Model Tests  
Our preliminary work in the TJ-6 wind tunnel indicated that simulating the original non-stationary ABL flow field or the senior sinusoidal flow field obtained by linearly superposing multiple basic sinusoidal waves as realized by the present numerical simulation (see Section 3.2) was difficult, but the individual flow fields with the input flow velocities varied according to the basic sinusoidal waves can be accurately simulated there. At present, a useful method should be conceived to facilitate the comparison based on the present experimental condition of TJ-6. To explore the relationships of wind effects on a circular cylinder obtained in multiple non-stationary sinusoidal wave flow fields, numerical analyses have been undertaken on a commercial CFD platform. Further, 2-D flows around a circular object with a diameter of 1.6459 m are simulated in three wind fields with the inlet velocities varied according to different sinusoidal functions. The inlet velocity time-histories for the three wind fields are shown in Figure 12. As can be seen, the velocity time-histories for Cases 1 and 2 are two different basic sinusoidal waves as they are of different periods; the velocity time-history for Case 3 is a senior sinusoidal  
Figure 11: Comparison of the three adverse effects. wave obtained by linearly superposing the velocity time-histories of Cases 1 and 2. The inlet boundary condition is of the velocity-inlet type, and the outlet boundary conditions are of the pressure-outlet type. The wind field is assumed to be a compressible flow field and the k-\(\varepsilon\) standard viscous model is utilized. Compressibility means that the density is noticeably increased and the volume is thereby decreased for the fluid flow under pressure, and this effect should not be neglected for fluids like the wind in CFD simulations or analytical calculations. A standard wall function is adopted for the near-wall treatment. The pressure-velocity coupling equations are solved with the second-order implicit steady formulation. The residual is set to 0.001, and the time step is 0.05 s.  
After the numerical simulations, the wind loads on the circular object calculated for different cases are obtained and compared in Figure 13. As can be seen, the wind pressure coefficient time-histories calculated at different positions for all three cases are all non-stationary as they are all time-variant throughout the wind events. Moreover, the three samples for Cases 1-3 are noticeably different at the late stage of the wind events in Figure 13. The pressure coefficients for Case 2 are generally greater than those for Case 1 at different positions, and the pressure coefficients for Case 3 are in between them. Taking a step further, the averaged pressure coefficients of Cases 1 and 2 are added in Figure 13, and it is noted that the averaged values are close to the pressure coefficients for Case 3. Since the flow field for Case 3 is the linear superposition of those for Cases 1 and 2, it can be tentatively inferred from the above observations that wind effects measured in a comparatively more complicated flow field obtained by linearly superposing two basic sinusoidal wave flow fields are approximately equal to the averages of wind effects measured in the individual basic sinusoidal wave flow fields. To take advantage of this finding, we can simulate multiple non-stationary flow fields in the TJ-6 wind tunnel first, with the input flow velocities varied according to the basic sinusoidal waves obtained earlier to approximate the IMFs shown in Figure 5. Then, pressure measurements can be taken on a scaled Pengcheng cooling tower model in these non-stationary flow fields in the TJ-6 wind tunnel. Finally, the results obtained in multiple non-stationary flow fields (pressure coefficient samples) can be averaged as the wind effects obtained in flow field B for use to facilitate the new full-scale/model test comparison of wind effects on Pengcheng cooling tower.