computers has increased so too has the level of sophistication
of CFD packages. Therefore, it is necessary to exploit
the power of CFD as best as possible in each simulation.
An examination of turbulence models used in ventilation
system modelling has shown that the quality of a solution
is highly dependant on the turbulence model. The
standard k–e model, which still commonly used, at times
yields inadequate results and circumspective choice of
other turbulence models should be made depending on
the phenomena involved in the simulation.
The use of porous media models to simulate the pressure
drop over flow restrictors such as insect nets and fences is
popular in CFD simulations. These models used can be
altered depending on the scale and requirements of the simulation,
and the accuracy associated with their implementation
depend on the choices made by the modeller.
To ensure CFD simulations are more than just theoretical
exercises, experimental validation is necessary. Over
recent years this has been carried both in the laboratory,
using wind tunnel and salt water baths, and in full scale,
using tracer gas or sonic anemometry. New technologies
such as particle image velocitometry have also shown to
complement CFD predictions. Validation has been successful
in many cases and even in cases where discrepancies
exist, deficiencies in the model or measurement technique
were readily identifiable.
With regards to agricultural buildings, advances in CFD
technology has meant that field solutions can now include
dynamic biological responses of housed entities, and
thereby enhance the realism of the simulations. Greenhouse
CFD applications has been of a higher standard
than animal housing CFD applications over recent years,
owing to the incorporation of crop biological models in
computations. Recent studies have adopted similar techniques
in animal housing applications. Overall this review
underlines the scope which CFD can offer to indoor environmental
modelling and highlights the need for more
studies to focus on facility design rather than phenomena
observation.