Spectral Characteristics and Correlation of Dynamic Wind Loads of a Typical Super-Tall Building

2013 ◽  
Vol 351-352 ◽  
pp. 347-350
Author(s):  
Lun Hai Zhi

This paper present some selected results of wind tunnel tests carried out on a typical super-tall building The variations of wind loads in the three orthogonal directions with wind attack direction were evaluated. The cross-correlations among various wind loading components were presented and discussed in detail. Furthermore, the across-wind spectral characteristics were studied and an empirical formula for estimation of the across-wind overturning moment spectrum for the super-tall building is presented. The output of this study is expected to be of considerable interest and practical use to professionals and researchers involved in the design of super-tall buildings.

Author(s):  
Yi Li ◽  
Chao Li ◽  
Qiu-Sheng Li ◽  
Yong-Gui Li ◽  
Fu-Bin Chen

This paper aims to systematically study the across-wind loads of rectangular-shaped tall buildings with aerodynamic modifications and propose refined mathematic models accordingly. This study takes the CAARC (Commonwealth Advisory Aeronautical Research Council) standard tall building as a benchmark model and conducts a series of pressure measurements on the benchmark model and four CAARC models with different round corner rates (5%, 10%, 15% and 20%) in a boundary layer wind tunnel to investigate the across-wind dynamic loads of the typical tall building with different corner modifications. Based on the experimental results of the five models, base moment coefficients, power spectral densities and vertical correlation coefficients of the across-wind loads are compared and discussed. The analyzed results shown that the across-wind aerodynamic performance of the tall buildings can be effectively improved as the rounded corner rate increases. Taking the corner round rate and terrain category as two basic variables, empirical formulas for estimating the across-wind dynamic loads of CAARC standard tall buildings with various rounded corners are proposed on the basis of the wind tunnel testing results. The accuracy and applicability of the proposed formulas are verified by comparisons between the empirical formulas and the experimental results.


2016 ◽  
Vol 23 (3) ◽  
pp. 231-251
Author(s):  
Lianghao Zou ◽  
Guoji Xu ◽  
C.S. Cai ◽  
Shuguo Liang

1992 ◽  
Vol 19 (4) ◽  
pp. 711-723
Author(s):  
G. R. Lythe ◽  
D. Surry

This paper examines the mean and peak torsional wind loads on tall buildings using two data bases of torsion measured experimentally in wind tunnel tests: the first, a large data base of mean torsional loads; and the second, a smaller data base of peak torsions. Although the mean load constitutes only a part of the total peak load required for design, it provides considerable insight into the aerodynamics of torsion, while improvement in its estimation also improves the estimation of the total peak load, using empirical gust factor methods. Comparisons between experimental results and the corresponding provisions of the 1985 National Building Code of Canada and Commentary indicate that, while the NBCC is a good estimator of mean shear loads, it significantly underestimates the mean torsional loads on tall buildings. The experimental data are further analysed to provide an improved estimation method for both the mean and the peak torsion. For mean torsion, this involves evaluating various definitions of the torsion coefficient and classifying building shapes in order to decrease the variability of the associated coefficients. This process leads to some notion of those shapes susceptible to large torsional loads and the most important building parameters on which to base predictions. This insight, along with the data base of peak torsion, is used to simplify and improve an existing method for estimating peak torsion, which was developed using a smaller data base. Key words: torsion, wind loading, codes, wind tunnel tests, tall buildings.


Author(s):  
D G Thomson ◽  
F Coton ◽  
R Galbraith

The aim of this article is to investigate the use of inverse simulation to help identify those regions of a ship's flight deck which provide the safest locations for landing a rotorcraft in various atmospheric conditions. This requires appropriate information on the wind loading conditions around a ship deck and superstructure, and for the current work, these data were obtained from wind tunnel tests of a ship model representative of a typical helicopter carrier/assault ship. A series of wind tunnel tests were carried out on the model in the University of Glasgow's 2.65 × 2.04 m wind tunnel and three-axis measurements of wind speed were made at various locations on the ship deck. Measurements were made at four locations on the flight deck at three different heights. The choice of these locations was made on the basis of preliminary flow visualization tests which highlighted the areas where the most severe wind effects were most likely to occur. In addition, for the case where the wind was from 30° to starboard, measurements were made at three further locations to assess the extent of the wake of the superstructure. The generated wind profiles can then be imposed on the inverse simulation, allowing study of the vehicle and pilot response during a typical landing manoeuvre in these conditions. The power of the inverse simulation for this application is demonstrated by a series of simulations performed using configurational data representing two aircraft types, a Westland Lynx and a transport helicopter flying an approach and landing manoeuvre with the worst atmospheric conditions applied. It is shown from the results that attempting to land in the area aft of the superstructure in a 30° crosswind might lead to problems for the transport configuration due to upgusts in this area. Attempting to perform the landing manoeuvre in an aggressive manner is also shown to lead to diminished control margin in higher winds.


2010 ◽  
Vol 98 (12) ◽  
pp. 689-700 ◽  
Author(s):  
Samuel Amoroso ◽  
Kirby Hebert ◽  
Marc Levitan

1985 ◽  
Vol 1 (2) ◽  
pp. 105-110 ◽  
Author(s):  
A. J. Dutt

This paper deals with the investigation of wind loading on the pyramidal roof structure of the Church of St Michael in Newton, Wirral, Cheshire, England, by wind tunnel tests on a 1/48 scale model. The roof of the model was flat in the peripheral region of the building while in the inner region there was a grouping of four pyramidal roofs. Wind tunnel experiments were carried out; wind pressure distribution and contours of wind pressure on all surfaces of the pyramid roofs were determined for four principal wind directions. The average suctions on the roof were evaluated. The highest point suction encountered was — 4q whilst the maximum average suction on the roof was —0·86q. The results obtained from wind tunnel tests were used for the design of pyramidal roof structures and roof coverings for which localised high suctions were very significant.


2021 ◽  
Author(s):  
Zana Sulaiman

Abstract This paper presents the results of wind load computational fluid dynamics (CFD) calculations performed on the topside structures of a self-propelled wind turbine installation jack-up. The CFD calculations were performed for the jack-up topside structures with and without the deck load. An atmospheric boundary layer profile was applied for the model-scale calculations. The full range of heading angles was considered. The CFD results were validated through comparison with the wind tunnel tests which were carried out at the German-Dutch wind tunnels (DNW) in Marknesse, The Netherlands. Moreover, a comparison is presented between the applied boundary layer profiles throughout the CFD computational domain with those profiles measured in the wind tunnel. The CFD results were found to be in good agreement with the wind tunnel tests for the considered cases, verifying the feasibility of the CFD method as an important design tool for the prediction of wind loads during the design processes of these types of jack-ups.


Author(s):  
Astha Verma ◽  
Ashok Kumar Ahuja

Wind is one of the important loads to be considered while designing the roofs of low-rise buildings. The structural designers refer to relevant code of practices of various countries dealing with wind loads while designing building roofs. However, available information regarding wind pressure coefficients on cylindrical roofs is limited to single span only. Information about wind pressure coefficients on multi-span cylindrical roofs is not available in standards on wind loads. Present paper describes the details of the experimental study carried out on the models of low-rise buildings with multi-span cylindrical roofs in an open circuit boundary layer wind tunnel. Wind pressure values are measured at many pressure points made on roof surface of the rigid models under varying wind incidence angles. Two cases namely, single-span and two-span are considered. The experimental results are presented in the form of contours of mean wind pressure coefficients. Results presented in the paper are of great use for the structural designers while designing buildings with cylindrical roofs. These values can also be used by the experts responsible for revising wind loading codes from time to time.


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