NUMERICAL STUDY OF VENTILATION FLOW THROUGH A TWO DIMENSIONAL ROOM FITTED WITH A WINDCATCHER

A windcatcher is a natural ventilation device fitted on the roof of a building and divided internally into two halves to deliver fresh outside air into the building's interior, and induce the stale air to the outside, working by pressure difference between outside and inside of the building. In this work, air flow through a two-dimensional but real-sized room fitted with a windcatcher is investigated numerically, using a commercial computational fluid dynamics (CFD) software package. The standard K-å turbulence model is used. Flow pattern and flow velocity are considered in terms of the windcatchers location, inlet velocity, the shape of the windcatchers bottom and the length of the windcatchers bottom. It is found that when inlet velocity is not too low, the windcatcher's shape at its bottom strongly affects flow pattern and flow velocity in the room. This leads to a way of improving the windcatcher's effectiveness in ventilating the living area (lower part) of a room