scholarly journals Review of Wind Tunnel Modelling of Flow and Pollutant Dispersion within and from Naturally Ventilated Livestock Buildings

2021 ◽  
Vol 11 (9) ◽  
pp. 3783
Author(s):  
Štěpán Nosek ◽  
Zbyněk Jaňour ◽  
David Janke ◽  
Qianying Yi ◽  
André Aarnink ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Environmental Problem ◽  
Physical Modelling ◽  
Pollutant Dispersion ◽  
Promising Method ◽  
Wind Tunnels ◽  
Ammonia Emissions ◽  
Livestock Buildings

Ammonia emissions from naturally ventilated livestock buildings (NVLBs) pose a serious environmental problem. However, the mechanisms that control these emissions are still not fully understood. One promising method for understanding these mechanisms is physical modelling in wind tunnels. This paper reviews studies that have used this method to investigate flow or pollutant dispersion within or from NVLBs. The review indicates the importance of wind tunnels for understanding the flow and pollutant dispersion processes within and from NVLBs. However, most studies have investigated the flow, while only few studies have focused on pollutant dispersion. Furthermore, only few studies have simulated all the essential parameters of the approaching boundary layer. Therefore, this paper discusses these shortcomings and provides tips and recommendations for further research in this respect.

Numerical and Experimental Models of Load on Buldings from the Effects of the Atmospheric Wind

2014 ◽  
Vol 969 ◽  
pp. 280-287 ◽  
Author(s):  
Vladimira Michalcova ◽  
Sergej Kuznetsov ◽  
Stanislav Pospíšil
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Flow Field ◽  
Physical Modelling ◽  
Experimental Models ◽  
Applied Mechanics ◽  
Ansys Fluent ◽  
Commercial Code ◽  
Benchmark Solution ◽  
Wind Pressures

The paper describes two different approaches of the solution of benchmark solution of bluff aerodynamic, which is the solution of wind pressures upon the cube exposed to the effects of air flow field. Two tasks are discussed in this article. One has the flow field with the constant wind velocity and low turbulence intensity, while the second one simulates the flow in the simulated Atmospheric Boundary Layer. Physical modelling is carried out at the wind tunnel of the Institute of Theoretical and Applied Mechanics in Telč. Numerical modelling is carried out at the Department of mechanics, Faculty of Civil Engineering, Technical University of Ostrava. Commercial code Ansys - Fluent has been used for the calculation.

Uncertainty Evaluation of Friction Velocity Measurements by Oil-Film Interferometry

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
René Thibault ◽  
Gérard J. Poitras
Keyword(s):  
Boundary Layer ◽  
Shear Stress ◽  
Wind Tunnel ◽  
Friction Velocity ◽  
Standard Uncertainty ◽  
Roughness Height ◽  
Wind Tunnels ◽  
Roughness Parameters ◽  
Oil Viscosity ◽  
Fringe Spacing

Wind loads on structures and the wind environment around buildings are based on tests in boundary layer wind tunnels with corresponding scale parameters. The lower part of the troposphere boundary layer was simulated inside a small wind tunnel located at the Wind Engineering Centre of the Université de Moncton. The correct scale ratios of the boundary layer thickness combined with the roughness height are two of the most important scales to match. For small wind tunnels, roughness parameters related to the model boundary layer can be difficult to measure since scale ratios for wind load studies are expected to be in the range of 400–1000. Oil-film interferometry was used to determine the roughness parameters (shear stress, friction velocity, and roughness height) of the forced turbulent boundary layer inside the wind tunnel. In this work, the International Organization for Standardization (ISO) Guide to Expression of Uncertainty in Measurements was used to evaluate the standard uncertainty of the roughness parameters on the bottom wall of the wind tunnel. The standard uncertainty of the roughness parameters depends strongly on the oil viscosity and on the accurate measurement of the fringe spacing. Results show that the standard uncertainty of the shear stress and friction velocity determined by the interferometry technique can be less than 5% when the oil viscosity and the fringe spacing can be accurately measured with a standard uncertainty lower than 4% and 1%, respectively.

Wind-tunnel simulation of the atmospheric boundary layer: a report on Euromech 50

1975 ◽  
Vol 70 (3) ◽  
pp. 543-559 ◽  
Author(s):  
J. C. R. Hunt ◽  
H. Fernholz
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Atmospheric Boundary Layer ◽  
Boundary Layers ◽  
Wind Tunnels ◽  
Atmospheric Conditions ◽  
Atmospheric Boundary Layers ◽  
Future Developments ◽  
Wind Tunnel Simulation

The 50th Euromech Colloquium, on wind-tunnel simulation of the atmospheric boundary layer, was held in Berlin from 23–25 September 1974. Thirty-eight participants from eleven countries were present. Papers were presented describing and analysing different methods of simulation of neutral, stable and unstable atmospheric conditions in various types of wind tunnel. Numerous applications of wind-tunnel simulations were described or mentioned in the papers and the discussion sessions. Some conclusions about the validity, the techniques, the limitations and future developments of wind-tunnel simulations were reached in discussion. Tables are presented in appendix A listing the institutes in Europe and the U.S.A. of actual or invited participants where wind tunnels are used for simulation work; also listed are the characteristics of the wind tunnels and relevant measurements of the simulated atmospheric boundary layers, to enable comparisons to be made between different techniques.

Boundary layer wind tunnel modeling experiments on pumping ventilation through a three-story reduce-scaled building with two openings

2021 ◽  
pp. 108043
Author(s):  
Huai-Yu Zhong ◽  
Chao Lin ◽  
Yang Sun ◽  
Hideki Kikumoto ◽  
Ryozo Ooka ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel

Air flow quality analysis of an open-circuit boundary layer wind tunnel and comparison with a closed-circuit wind tunnel

2020 ◽  
Vol 32 (12) ◽  
pp. 125120
Author(s):  
María Jiménez-Portaz ◽  
Luca Chiapponi ◽  
María Clavero ◽  
Miguel A. Losada
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Air Flow ◽  
Open Circuit ◽  
Closed Circuit ◽  
Quality Analysis ◽  
Flow Quality

Influence of the Side Walls on the Turbulent Center-Plane Boundary-Layer in a Square Duct

1978 ◽  
Vol 100 (1) ◽  
pp. 91-96 ◽  
Author(s):  
V. de Brederode ◽  
P. Bradshaw
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Flat Plate ◽  
Cross Section ◽  
Secondary Flows ◽  
Plane Boundary ◽  
Square Duct ◽  
Streamwise Pressure Gradient ◽  
Side Walls ◽  
Working Section

Measurements in the entry region of a square duct (specifically, a wind-tunnel working section) show that the direct effect of stress-induced secondary flows in the corners on the center-plane boundary layer is negligible for boundary layers thinner than about one-fourth of the duct width. Further, the effects of streamwise pressure gradient and of quasi-collinear lateral convergence tend to cancel so that the velocity profiles and skin friction are quite close to those on a flat plate. This shows that the boundary layer on the floor of a wind tunnel of constant, square cross section can be used to simulate a flat-plate flow even when the boundary layer thickness is as large as one-fourth of the tunnel height.

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