page_title: CFD in buildings
section_title: Orientation, site and location selection
hierarchical_section_title: CFD in buildings / Applications / Orientation, site and location selection
caption_attribution_description: English: my own work
context_page_description: CFD stands for computational fluid dynamics. As per this technique, the governing differential equations of a flow system or thermal system are known in the form of Navier–Stokes equations, thermal energy equation and species equation with an appropriate equation of state. In the past few years, CFD has been playing an increasingly important role in building design, following its continuing development for over a quarter of a century. The information provided by CFD can be used to analyse the impact of building exhausts to the environment, to predict smoke and fire risks in buildings, to quantify indoor environment quality, and to design natural ventilation systems.
context_section_description: Earlier, the choice of dwelling location was made mindful of the need for water, so most of earlier development started in valley area. In present era, due to advancement in science and technology, it becomes easy to select a proper orientation, site and location of buildings based on local geographical and environmental conditions. In selection of building site and location, wind loading plays and important role. In case of two buildings at a location exists side by side having some gap, when volume of wind blows round the ends of building through the gap is, in first instant the sum of flow around each building separately, then its velocity must increase above that around the end of a single building at the expense of pressure loss.
  So, there will be a built of pressure, entering the gap, which will lead to higher wind loads on the sides of buildings. When wind blows over the face of a high rise building, a vortex is created by the downward flow on the front face (as shown in figure-1). The wind speed in the reverse direction near the ground level may have 140 percent of the reference wind speed. So, if any building exist in such region, then that may be subjected to damage (especially the roof of building may get severe damage). Such damage to buildings can be prohibited successfully, if the effects of wind loading are considered in the early stage of construction of a building. In early age of construction all these wind loading effects were determined by the wind tunnel test, but today all these test can be successfully through CFD analysis. The importance of providing pleasant environment to buildings is increasing. Architects and wind engineers are often asked to look over the design (orientation, site, location and gaps between the surrounding buildings) in the formative stage of buildings & planning stage of construction. So by using CFD analysis, it is possible to find the suitable information (local wind velocity, convective coefficients, and solar radiation intensity) for orientation, site and location selection of buildings.
caption: Figure-1 (a): Flow around a building (collection of air at height and delivering it at ground level)
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