No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Wind loads on high-rise buildings: A comparison between CFD simulations and wind tunnel benchmark for the mean base moment
Abstract
At present, results from scaled wind tunnel tests are the most accepted
depiction of the real behaviour of high-rise buildings in the wind. For buildings with sharp edges the accuracy is considered to be reliably high. Confidence in the application of CFD simulations in the field of wind engineering still has to grow. Running CFD simulations at full-scale can provide a possible benefit over wind tunnel simulations. However, the resulting high Reynolds numbers are a challenge. Increasing computer power and research on the reliability of CFD are required. In this study CFD simulations at full scale (Reynolds number 108) are undertaken for the wind tunnel benchmark study from Holmes and Tse (2014) based on the CAARC building. Steady RANS simulations with the analytical atmospheric boundary condition from Richards and Hoxley (1993) at the inlet are conducted with different meshing topologies and grid refinement steps, in order to obtain the mean base moment for different angles. Even with a basic CFD setup, the results show a remarkable similarity with the wind tunnel results for the base moments in along- and across-wind direction. For the rotational moment the wind tunnel results exposed larger variations, and so do the CFD results. However, the values are well within the magnitude of the wind tunnel results.
ResearchGate has not been able to resolve any citations for this publication.
The guideline for CFD prediction of wind environment around buildings was proposed by Working Group of the Architectural Institute of Japan (AIJ). It is described based on the results of benchmark tests which have been conducted for investigating the influence of many kinds of computational conditions for various flowfields. This paper delineates the guideline proposed by our group. 1 INTRODUCTION As computer facilities and Computational Fluid Dynamics (CFD) software have been improved in recent years, the prediction and the assessment of wind environment around buildings using CFD have become practical at design stages. Therefore, a guideline which summarizes important points of using CFD technique for appropriate prediction of wind environment is needed. Although there have been the recommendations with similar objectives proposed by COST group [1], those are mainly based on the results published elsewhere. On the other hand, the guideline proposed by AIJ is based on the results of benchmark tests which have been conducted to investigate the influence of many kinds of computational conditions for various flowfields by our own [2-6]. This paper briefly summarizes the guideline and the full version of the guideline will be available in the final paper. This guideline is mainly based on using high Reynolds (Re) number RANS (Reynolds Averaged Navier-Stokes equations) models. In order to obtain more accurate result, it is desirable to use a Large Eddy Simulation (LES) and a low Re number type model. However, it is difficult to use those models for practical analysis because many computational cases and a huge number of grids are required for the prediction and analysis of wind environment under severe time restrictions. If it is necessary to use a highly accurate model like LES or low Re number type model, it is recommended to use it after the calculations and analysis which have been done by high Re number type RANS models following this guideline.
A numerical study of the wind speed conditions in passages between parallel buildings has been conducted for a wide range of passage widths with the commercial Computational Fluid Dynamics (CFD) code Fluent 6.1.22. CFD validation has been performed by comparison of the numerical results with the corresponding wind tunnel measurements. The study shows that accurate CFD simulation of a horizontally homogeneous atmospheric boundary layer (ABL) flow and of the subsequent building-related flow might be seriously compromised by the use of the wall-function roughness modifications present in many commercial CFD codes. In addition, the simulation results indicate that, at least for the cases studied here, the increase of wind speed in passages is only pronounced at the pedestrian level and that the flow rate through the passage is at most only 8% higher than the free-field flow rate, indicating that the so-called Venturi-effect is rather weak.
Best practice guideline for the CFD simulation of flows in the urban environment: COST action 732 quality assurance and improvement of microscale meteorological models
- J Franke
- A Hellsten
- H Schlünzen
- B Carissimo
Franke J, Hellsten A, Schlünzen H and Carissimo B (2007). Best practice guideline for the CFD simulation of
flows in the urban environment: COST action 732 quality assurance and improvement of microscale
meteorological models. Meteorological Institute, Hamburg
International high-frequency base balance benchmark study. Wind and Structures 18
- J D Holmes
- T K Tse
Holmes J D and Tse T K (2014). International high-frequency base balance benchmark study. Wind and
Structures 18, http://dx.doi.org/10.12989/was.2014.18.4.4
Appropriate boundary conditions for computational wind engineering models using the k-ε turbulence model
- P J Richards
- R P Hoxey
Richards P J and Hoxey R P (1993). Appropriate boundary conditions for computational wind engineering
models using the k-ε turbulence model. Journal of Wind Engineering and Industrial Aerodynamics
46: https://doi.org/10.1016/0167-6105(93)90124-7
Statement of CFD and wind tunnel testing for wind engineering of buildings
- Rwdi
RWDI (2021). Statement of CFD and wind tunnel testing for wind engineering of buildings,
https://rwdi.com/en_ca/insights/thought-leadership/statement-on-cfd-and-wind-tunnel-testing-forwind-engineering-of-buildings. Accessed 29.11.2021, 08:15