Abstract
Enclosure sampling devices, such as wind tunnels and flux chambers, are commonly applied to quantify the emission rate of odorous compounds at passive liquid surfaces. As the aerodynamics of such devices is of great importance for the accuracy of results, proper evaluation methods are highly desired. Computational Fluid Dynamics (CFD) is one of these potential tools, to be used in complement to other methodologies. This paper is aimed to discuss aspects related to the use of CFD in the analysis of a wind tunnel device for sampling of odorous emissions at liquid surfaces. A CFD simulation of the wind tunnel that was developed at the University of New South Wales (UNSW wind tunnel) is used as an example- case to develop the discussion, describing the general steps that comprise a CFD study. Special attention is given to the validation step, exploring and discussing possibilities of validation against experimental data and theoretical models. It is shown, for this case, validation using published experimental data is particularly difficult. On the other hand, comparison with a theoretical boundary layer model suggests that the simulation represented an ideal (two-dimensional) situation for the wind tunnel, presenting an expected slightly difference in comparison with Blasius boundary layer description. Such deviations as well as the potential effect of a three-dimensional geometry are important considerations when dealing with practical situations.
