Paper 2: Volume 4 No.2 September 2005 Edition
Numerical and
Experimental Investigation of a Mechanically Ventilated Room: The Impact
of Inlet Boundary Conditions on CFD Modelling of the Ventilation System
Frédéric
Kuznik and Jean Brau
Thermal
Sciences Center, National Institute of Applied Sciences,
Lyon
Bât.
Freyssinet, 20av. A. Einstein – 69621
Villeurbanne
Cedex
,
France
Abstract
Among the tools which
serve to predict heat and mass transfer in a mechanically ventilated room,
CFD is increasingly used. However, this type of tool needs a correct
description of the boundary conditions, especially concerning the air
inlet. The ventilation inlet is often geometrically complex and many
models exist in order to simplify their equivalent boundary conditions
included in CFD codes. Nevertheless, none of these simplified models can
predict the correct behaviour of flows issuing, for example, from a
T-pipe, a bend or a more complex ventilation system. The main idea is then
to model a part of the ventilation system with the help of CFD and to
impose boundary conditions on a fully developed flow section situated far
from the inlet. The validation of this approach consists of the comparison
of experimental and numerical data obtained for a mechanically ventilated
room with and without thermal effects. This model has also been tested
with more complex diffusers to show its broader scope.
Key words: CFD modelling, ventilation system, air inlet models,
comparison with measurement, MINIBAT.
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