Computational fluid dynamics, a building simulation tool for achieving sustainable buildings

Buildings use about 40% of the global energy, thus making them the prime consumers and therefore the center of attention. The analysis of most of the building related problems such as the thermal analysis, effects of wind loading, ventilation analysis and the environmental effects etc. were conducted by the wind tunnel tests, earlier. However, now days, all these test can be done effectively with the aid of a mathematical technique called computational fluid dynamics (CFD). This paper is a brief, non-exhaustive overview of the status of application of CFD in building performance simulation for the indoor and outdoor environment. The discussion is focused on the management of the thermal comfort based on the ventilation loss, thermal loss and some other topics like the effect of fire inside the building and the hospital environment along with the discussions on the movement of the pedestrians, effect of rain and wind or wind driven rain (WDR) and pollutants etc. on the buildings especially artifacts. It is seen that CFD technique offers many advantages over the wind tunnel testing and simplified empirical or semi-empirical equations. Deficiencies of steady RANS and LES modeling, the need for high-resolution grids and lastly, the requirement of a valid CFD model and its verification poses some limitations. Still efforts are being done and shall continue to focus on alleviating these limitations, but at least equally important is avoiding user errors.