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CONTENTS
Volume 35, Number 6, December 2022
 


Abstract
Wind tunnel experiment was carried out to study the cross-wind layer forces on a square cross-section building model using a synchronous multi-pressure sensing system. The stationarity of measured wind loadings are firstly examined, revealing the non-stationary feature of cross-wind forces. By converting the measured non-stationary wind forces into an energetically equivalent stationary process, the characteristics of local wind forces are studied, such as power spectrum density and spanwise coherence function. Mathematical models to describe properties of cross-wind forces at different layers are thus established. Then, a conditional simulation method, which is able to ex-tend pressure measurements starting from experimentally measured points, is proposed for the cross-wind loading. The method can reproduce the non-stationary crosswind force by simulating a stationary process and the corresponding time varying amplitudes independently; in this way the non-stationary wind forces can finally be obtained by combining the two parts together. The feasibility and reliability of the proposed method is highlighted by an ex-ample of across wind loading simulation, based on the experimental results analyzed in the first part of the paper.

Key Words
conditional simulation; cross-wind loading; high-rise building; mathematical modeling; non-stationary forces

Address
Ailin Zhang and Shi Zhang:School of Civil and Transportation Engineering, Beijing University of Civil Engineering and Architecture, No.1 Zhanlanguan Road,
Xicheng District 100044 Beijing, China

Xiaoda Xu:Central Research Institute of Building and Construction CO., LTD. MCC, No.33 Xitucheng Road, Haidian District 100088 Beijing, China

Yi Hui:School of Civil Engineering, Chongqing University, No. 83 Shabei Street, Shapingba District, 400045 Chongqing, China

Giuseppe Piccardo:Department of Civil, Chemical and Environmental Engineering – DICCA, University of Genoa, Via Montallegro, 1, 16145 Genoa, Italy

Abstract
The energy demand of the world is increasing rapidly, mainly using fossil energy, which causes environmental damage. The wind is free and clean energy to solve the environmental problems. Thailand is one of the developing nations, and the majority of its energy is obtained from petroleum, natural gas and coal. The objective of this study is to test the characteristics of wind energy at Khon Kaen in Thailand. The wind measurement tools, the 3-cup anemometers to measure wind speed, and wind vanes to measure wind direction, were mounted on a wind tower mast to record wind data at the heights of 60, 90 and 120 meters above ground level (AGL) for 5 years between January 2012 and December 2016. The results show that the annual mean wind speeds were 3.79, 4.32 and 4.66 m/s, respectively. The highest mean wind speeds occurred in June, August and December, in order, and the lowest occurred in September. The majority of prevailing wind directions were from the NorthEast and South-West directions. The average annual wind shear coefficient was 0.297. Furthermore, five wind turbines with rated power from 0.85 to 4.5 MW were selected to estimate the wind energy output and it was found that the maximum AEP and CF were achieved from the low cut-in speed and high hub-height wind turbines. This important information will help to develop wind energy applications, such as the plan to produce electricity and the calculation of the wind load that affects tall and large structures.

Key Words
tall building; vertical profile; wind energy; wind load; wind speed

Address
Supachai Polnumtiang:Mechanical Engineering Department, Faculty of Engineering, Khon Kaen University (KKU), Thailand

Kiatfa Tangchaichit:Center for Alternative Energy Research and Development, Khon Kaen University (AERD-KKU), Thailand

Abstract
The present research is concerned with the study of Stoneley wave propagation at the interface of two dissimilar homogeneous orthotropic magneto-thermoelastic solids with fractional order theory of type GN-III with three phase-lags and combined effect of hall current and rotation. With the help of appropriate boundary conditions the secular equations of Stoneley waves are obtained in the form of determinant. The characteristics of wave such as phase velocity, attenuation coefficient and specific loss are computed numerically. The effect of rotation on the Stoneley wave's phase velocity, attenuation coefficient, specific loss, displacement components, stress components and temperature change has been depicted graphically. Some particular cases are also derived in this problem.

Key Words
attenuation coefficient; fractional order; hall current; orthotropic medium; phase velocity; rotation; specific loss; Stoneley wave propagation; three phase-lags

Address
Parveen Lata and Himanshi:Department of Basic and Applied Sciences, Punjabi University, Patiala, Punjab, India


Abstract
The aerodynamic behaviour of a CRH high-speed train under three infrastructure scenarios (flat ground, embankment, and viaduct) in the presence of a crosswind was simulated using a 1/8th scaled train model with three cars and the IDDES framework. The time-averaged and instantaneous flow field around the model were examined. The employed numerical algorithm was verified through a wind tunnel test, and the grid and timestep resolution analyses were conducted to ensure the reliability of the data. It was noted that the flow around the rail line was different under different infrastructure scenarios, especially in the case of the embankment, which degraded the aerodynamic performance of the train under the crosswind. The flow around the train on the flat ground and viaduct was different, although the aerodynamic performance of the train was similar in both cases. Moreover, the viaduct accidents were noted to have the most critical consequences, thereby requiring the most attention. The aerodynamic performance of the train on the windward track of the embankment under the crosswind was worse than that of the train on the leeward track. But for the other two infrastructure scenarios, the aerodynamic performance of the train on the windward track is relatively dangerous, which is mainly caused by the head car. These observations suggest that the aerodynamic behaviour of the train on an embankment under a crosswind must be carefully considered and that certain wind protection measures must be adopted around rail lines in windy areas.

Key Words
aerodynamic behaviour; crosswind; high-speed train; IDDES; infrastructure scenario

Address
Jiqiang Niu: 1)State Key Laboratory of Automotive Simulation and Control, College of Automotive Engineering, Jilin University,
Changchun 130025, Jilin, China
2)School of Mechanical Engineering, Southwest Jiaotong University, Chengdu 610031, Sichuan, China

Yingchao Zhang:State Key Laboratory of Automotive Simulation and Control, College of Automotive Engineering, Jilin University,
Changchun 130025, Jilin, China

Zhengwei Chen:Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University,
Hung Hom, Kowloon, Hong Kong, China

Rui Li:School of Mechanical Engineering, Lanzhou Jiaotong University, Lanzhou 730070, Gansu, China

Huadong Yao:Department of Mechanics and Maritime Sciences, Chalmers University of Technology, Gothenburg, 41296, Sweden

Abstract
In wind-resistant designs, wind velocity is assumed to be a Gaussian process; however, local complex topography may result in strong non-Gaussian wind features. This study investigates the non-Gaussian wind features over complex terrain under atmospheric turbulent boundary layers by the large eddy simulation (LES) model, and the turbulent inlet of LES is generated by the consistent discretizing random flow generation (CDRFG) method. The performance of LES is validated by two different complex terrains in Changsha and Mianyang, China, and the results are compared with wind tunnel tests and onsite measurements, respectively. Furthermore, the non-Gaussian parameters, such as skewness, kurtosis, probability curves, and gust factors, are analyzed in-depth. The results show that the LES method is in good agreement with both mean and turbulent wind fields from wind tunnel tests and onsite measurements. Wind fields in complex terrain mostly exhibit a left-skewed Gaussian process, and it changes from a softening Gaussian process to a hardening Gaussian process as the height increases. A reduction in the gust factors of about 2.0%-15.0% can be found by taking into account the non-Gaussian features, except for a 4.4% increase near the ground in steep terrain. This study can provide a reference for the assessment of extreme wind loads on structures in complex terrain.

Key Words
atmospheric turbulent boundary layers; complex terrain; gust factor; LES; non-Gaussian wind features

Address
Hongtao Shen:PowerChina Sichuan Electric Power Engineering Co., Ltd., Chengdu, 610016, China

Weicheng Hu:1)Institute for Smart Transportation Infrasture, School of Transportation Engineering,
East China Jiaotong University, Nanchang, 330013, China
2)Chongqing Key Laboratory of Wind Engineering and Wind Energy Utilization, School of Civil Engineering,
Chongqing University, Chongqing, 400044, China
3)Zhejiang Jiangnan Project Management Co., Ltd., Hangzhou, 310007, China

Qingshan Yang:Chongqing Key Laboratory of Wind Engineering and Wind Energy Utilization, School of Civil Engineering,
Chongqing University, Chongqing, 400044, China

Fucheng Yang:PowerChina Sichuan Electric Power Engineering Co., Ltd., Chengdu, 610016, China

Kunpeng Guo:Chongqing Key Laboratory of Wind Engineering and Wind Energy Utilization, School of Civil Engineering,
Chongqing University, Chongqing, 400044, China

Tong Zhou:Department of Civil Engineering, School of Engineering, The University of Tokyo, Tokyo, 113-8656, Japan

Guowei Qian:Department of Civil Engineering, School of Engineering, The University of Tokyo, Tokyo, 113-8656, Japan

Qinggen Xu:Jiangxi Provincial Architectural Design and Research Institute Group Co., Ltd., Nanchang, 330046, China

Ziting Yuan:School of Civil Engineering and Architecture, Nanchang Jiaotong Institute, Nanchang, 330100, China


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