# The Spatial Structure of Passively Simulated Atmospheric Boundary Layer Turbulence  
[PERSON]  
1 College of Civil Engineering and Architecture, Hainan University, Haikou 570228, China; [EMAIL_ADDRESS]  
[PERSON]  
1 College of Civil Engineering and Architecture, Hainan University, Haikou 570228, China; [EMAIL_ADDRESS]  
[PERSON]  
2 Key Laboratory for Wind Engineering of Sichuan Province, Southwest Jiaotong University, Chengdu 610031, China; [EMAIL_ADDRESS] (M.L. ); [EMAIL_ADDRESS] (Z.L.) [PERSON]  
2 Key Laboratory for Wind Engineering of Sichuan Province, Southwest Jiaotong University, Chengdu 610031, China; [EMAIL_ADDRESS] (M.L. ); [EMAIL_ADDRESS] (Z.L.) Correspondence: [EMAIL_ADDRESS]; Tel. : +86-0898-66279232  
layer turbulence, including the wind profile, integral scale, wind spectrum, and coherence function, were conducted by [PERSON] [10], [PERSON] [11], [PERSON] [12], [PERSON] [13], and [PERSON] [14], among others, and they provided valuable references for engineering practice. Although field measurement plays an important role in the study of turbulence characteristics, it must be noted that it is generally difficult to achieve due to uncontrollable factors such as the long measurement period and high costs [15]. Many researchers have studied the spatial characteristics of the boundary layer using theoretical analyses or numerical simulations, resulting in a variety of solutions to complex turbulence problems [1; 3; 8; 16; 17]. Many classic turbulence theory models, such as isotropic turbulence theory and related improved models, have been developed [1; 3; 5; 18]. However, deriving the turbulence theory and solving the motion equation are extremely difficult [2; 9; 19]. Although turbulent problems can be solved using a variety of assumptions and simplifications, obtaining theoretical or numerical solutions that are completely consistent with the actual situation is difficult [20; 21]. The complexity and the uncertainty of the theoretical and numerical methods are not conducive to wider applications in the field of wind engineering, and further development is required [22]. With the advancement of experimental technology, many researchers have attempted to simulate atmospheric boundary layer turbulence using wind tunnels, and this method has gradually become one of the most important research methods in the field of structural wind engineering [23; 24]. After much research, it has become possible to simulate wind fields that are similar to natural wind and even unusual wind fields, such as typhoons and downbursts [25]. Turbulent wind fields simulated by wind tunnels have some issues that cannot be overlooked due to some technical limitations. That is, it is difficult to ensure that all of the statistical parameters of the simulated turbulent flow such as the wind velocity profile, the turbulence intensity, and the integral length scale are consistent with natural wind. However, the wind tunnel test has the advantages of a consistent performance and high work efficiency, and it is still an effective research method for wind engineering research [26; 27]. As a result, research into the spatial structure of simulated turbulent flow, as well as comparisons with field measurements or theoretical results, can aid in achieving a better understanding of its properties. Based on this, describing its spatial structure with reference to existing theoretical models will help improve wind tunnel test technology and enhance the reliability of wind engineering research. This study focused on the spatial characteristics of atmospheric boundary layer turbulence passively simulated by a wind tunnel, and it attempted to improve the relevant theoretical expressions based on experimental data. Combined with the existing turbulence theory, the 3D spatial characteristics of the simulated turbulence were analyzed in conjunction with the existing turbulence theory, and the lateral and vertical correlations of various fluctuating velocity components were extensively discussed. Theoretical predictions were compared to observed data.