## 3 Case Study: Peng-Cheng Cooling Tower
### Full-Scale Measurements  
During its construction, 36 pressure transducers were evenly installed around the targeted tower's throat section at 130 m high (see Figures 3 and 4). The whole full-scale measurement campaign lasted from 2010 to 2015 on a basis of 2-3 times of intensive tests per year. Among the large amount of data measured, those obtained from 28 November 2011, to 12 December 2011, are found to be most representative. During that period of time, only wind speeds for 29 November and 8 December exceeded 12 m/s, which represents valid strong wind scenarios. However, on 8 December, the incoming flow is from due north, and it is from due east on 29 November. As some transducers installed on the tower's north surface are found ineffective, complete wind effects around a half-circle can only be obtained on 29 November. In addition, the upstream terrain is smooth, and there are no obvious interference effects caused by neighboring cooling towers or buildings with respect to the specific wind direction of 29 November. As a result, the wind-induced pressures recorded on 29 November in 2011 are used. After processing the data measured on 29 November in 2011, the mean and the fluctuating wind pressure distributions around the throat section of the prototype Peng-cheng cooling tower are obtained for the case study. More details of the full-scale measurement campaign can be found in Refs. [20; 21; 22]. As suggested in Refs. [20; 21; 22], most technical issues concerning field pressure measurements on full-scale buildings perplexing the wind engineering community were well solved by the  
Figure 4: Projection of measuring tower (unit: m). Figure 3: Plan of pressure measurement points. Peng-cheng tower measurement campaign, which included a key technical difficulty, i.e., the establishment of the reference static pressure for the pressure measurements on location. Different from the traditional unreliable method of directly measure the reference static pressure on location, the present measurement campaign proposes and utilizes a simple but effective method to calculate the reference static pressure from the field measurement data. It is detailed below. According to Refs. [20; 23], the reference static pressure traditionally established for the pressure measurements on full-scale structures by using a pressure transducer arranged inside a cabin near the location cannot play the same role as the static pressure in the wind tunnel. Consequently, this article suggests using the reference static pressure calculated from the total wind pressures measured on a point with an invariant mean wind pressure coefficient. For this new method to take place, a 1:200-scaled pressure measurement model test for a 177 m high free-standing cooling tower located in Type B ABL flow field was undertaken in the TJ-3 wind tunnel at Tongji University. The details of the test have been reported in Ref. [22], and the results of the mean wind pressure distributions measured around the tower model at different turbulence intensities are shown in Figure 5. As shown in Figure 5, the mean wind pressure coefficients do not change noticeably at different turbulence intensities at the windward region (0-60 degrees) and the leeward region (120-180 degrees); however, they significantly change at the side region (60-120 degrees). The region between 60 and 120 degrees is also called the vortex separation zone, because vortexes are formed and separated near that position. The physical phenomenon of vortex shedding has been defined as alternating vortex shedding from the cylinder and a clear \"vortex trail\" formed downstream. According to [PERSON] and [PERSON] [24], the free-stream turbulence strongly influences the vortex shedding phenomenon, with the flow past a circular cylinder with regard to the Strouhal number, the span-wise correlation of vortices and the mean wind pressure coefficients in the vortex separation zone.