LES of geometric eccentricity effects on flow field and aerodynamic forces of T-shaped towers

Abstract

To investigate the aerodynamic performance of geometrically eccentric structures, wind tunnel testing and numerical simulations were employed to examine the flow field characteristics and tri-component aerodynamic forces of T-shaped towers with varying geometric eccentricities. A mathematical model for their generalized force spectra was established. The reliability of the numerical simulation method was validated by comparing the lift, drag, and torque coefficients obtained from wind tunnel experiments with the numerical results. Subsequently, the influence of geometric eccentricity on wind pressure distribution, vortex shedding characteristics, and turbulent kinetic energy distribution was analyzed. Using random vibration theory, a normalized formula for the full-tower force spectrum of the T-shaped tower was derived through nonlinear fitting of numerical simulation data. The results indicate that with increasing eccentricity, the vortex shedding of the structure becomes more complex, with a bias toward the eccentric side. Its wake morphology undergoes distortion and deformation, exhibiting vertical extensibility and leading to peak wind pressure occurring at the longer cross-arm. Furthermore, the torque coefficient demonstrated the highest sensitivity to eccentricity variations. A 50% increase in eccentricity resulted in a 99.7% increase in the torque coefficient.

Keywords

geometric eccentricity / T-shaped towers / aerodynamic forces / flow field characteristics

References

[1] CHEN X Z, KAREEM A. Coupled dynamic analysis and equivalent static wind loads on buildings with three-dimensional modes[J]. Journal of Structural Engineering, 2005, 131(7): 1071-1082.

[2] HOU F W, JAFARI M. Investigation approaches to quantify wind-induced load and response of tall buildings: A review[J]. Sustainable Cities and Society, 2020, 62: 102376.

[3] FU X, LI H N, LI G, et al. Advances in calculation theory of wind and rain loads and failure estimation for transmission tower-line systems[J]. Journal of Building Structures, 2023, 44(3): 198-212. (in Chinese)

[4] LIU Y D, LIN Y X, CHEN Y, et al. Wind-induced response analysis of transmission tower based on a novel analytical tornado model[J]. Journal of Southeast University (Natural Science Edition), 2025, 55(1): 124-130. (in Chinese)

[5] LIN Z Y, LI M, ZHANG H C, et al. Influence of wind barriers on aerodynamic forces of vehicles on bridge decks at different wind attack angles[J]. Journal of Southeast University (Natural Science Edition), 2025, 55(1): 154-160. (in Chinese)

[6] LI J K, MA C M, WU B, et al. Experimental investigation in nonlinear aerodynamic characteristics of a double-layer truss girder[J]. Journal of Fluids and Structures, 2025, 134: 104284.

[7] BAI H M, WANG N N, WAN D C. Numerical study of aerodynamic performance of horizontal axis dual-rotor wind turbine under atmospheric boundary layers[J]. Ocean Engineering, 2023, 280: 114944.

[8] MA T T, ZHAO L, SHEN X M, et al. Case study of three-dimensional aeroelastic effect on critical flutter wind speed of long-span bridges[J]. Journal of Wind Engineering and Industrial Aerodynamics, 2021, 212: 104614.

[9] WANG Y, CHEN X Z. Evaluation of wind loads on high-rise buildings at various angles of attack by wall-modeled large-eddy simulation[J]. Journal of Wind Engineering and Industrial Aerodynamics, 2022, 229: 105160.

[10] TANG L F, LIU H J, ZHENG C R. Investigation of the wind loads and flow patterns of a high-rise building under twisted wind flows based on LES[J]. Journal of Building Engineering, 2024, 96: 110478.

[11] LIU J Y, HUI Y, YANG Q S, et al. LES evaluation of the aerodynamic characteristics of high-rise building with horizontal ribs under atmospheric boundary layer flow[J]. Journal of Building Engineering, 2023, 71: 106487.

[12] LI Z H, WANG D H, CHEN X Z, et al. Wind load effect of single-column-supported two-plate billboard structures[J]. Journal of Wind Engineering and Industrial Aerodynamics, 2018, 179: 70-79.

[13] FENG Z Q, DENG J Y, HUA X G, et al. Flutter aerodynamic shape optimization method for streamlined box girders based on support vector regression with Bayesian optimization[J]. Journal of Southeast University (Natural Science Edition), 2024, 54(2): 275-284. (in Chinese)

[14] SHEN G, HAN K, LI B, et al. Mean wind loads on T-shaped angle transmission towers[J]. Wind and Structures, 2024, 38(5): 367-379.

[15] Ministry of Housing and Urban-Rural Development of the People’s Republic of China. Load code for building structures: GB 50009—2012[S]. Beijing, China: China Construction Industry Press, 2012. (in Chinese)

[16] American Society of Civil Engineers. Guidelines for electrical transmission line structural loading: ASCE NO. 74-2020[S]. Reston, VA, USA: American Society of Civil Engineers, 2020.

[17] GU M, QUAN Y. Across-wind loads and effects of super-tall buildings and structures[J]. Science China Technological Sciences, 2011, 54(10): 2531-2541.

[18] KWOK K C S. Cross-wind response of tall buildings[J]. Engineering Structures, 1982, 4(4): 256-262.

[19] LI Y, ZHANG J W, LI Q S. Experimental investigation of characteristics of torsional wind loads on rectangular tall buildings[J]. Structural Engineering and Mechanics, 2014, 49(1): 129-145.

[20] LI Y, LI Q S. Across-wind dynamic loads on L-shaped tall buildings[J]. Wind and Structures, 2016, 23(5): 385-403.

[21] HUANG S H, LI Q S, WU J R. A general inflow turbulence generator for large eddy simulation[J]. Journal of Wind Engineering and Industrial Aerodynamics, 2010, 98(10/11): 600-617.

[22] ZOU L, WU W N, WANG J H, et al. Numerical study on flow characteristics around wavy conical cylinders in triangular arrangement[J]. Journal of Southeast University (Natural Science Edition), 2024, 54(1): 224-231. (in Chinese)

[23] ZADOROZHNA D B, BENAVIDES O, GRAJEDA J S, et al. A parametric study of the effect of leading edge spherical tubercle amplitudes on the aerodynamic performance of a 2D wind turbine airfoil at low Reynolds numbers using computational fluid dynamics[J]. Energy Reports, 2021, 7: 4184-4196.

[24] ZHAO S, ZHANG X H, ZHANG C T, et al. Extreme-value combination rules for tower-line systems under non-Gaussian wind-induced vibration response[J]. Buildings, 2025, 15(11): 1871.

[25] HUANG S H, LI Q S, XU S L. Numerical evaluation of wind effects on a tall steel building by CFD[J]. Journal of Constructional Steel Research, 2007, 63(5): 612-627.

Funding

China Postdoctoral Science Foundation(2023T160767)

Natural Science Foundation of Chongqing Municipality(CSTB2023NSCQ-MSX0751)