Wind engineering is a crucial part of many construction projects. At heights of 400 m and above, the wind flow is similar to that experienced by an airplane. Our aim is to reduce the building’s movement to a level that its occupants are unaware of, and the challenge increases in proportion to the height of the building. This is particularly true of residential buildings, where the criteria are much more stringent than for commercial buildings.
Our solutions include adjusting the shape of a building to make it more aerodynamic, such as introducing openings to allow the wind to pass through, or adding curves at critical locations along the facade to minimize the “vortex shedding” response which causes high acceleration.
Using wind tunnel analysis, WSP works closely with architects to refine the shape of a building. Additionally, the use of high-strength concrete and a range of structural systems can improve a building’s stiffness without obstructing the layout. Very tall buildings also require a damper to slow the movement, leading structural engineers to seek ways to minimize material in order to reduce the costs and the impact on lettable space of the damper.
Tall towers influence their local microclimate, from blocking out the sun to creating wind tunnels and pockets where temperatures are noticeably cooler. They are designed to withstand the fierce winds that swirl around their upper reaches, but they also channel them down the length of their facades to the ground, disrupting life below. However, these effects can be mitigated, and that’s exactly what WSP’s microclimate specialists help clients to do.
We use wind modelling to identify any potential issues early on in the design process. By combining 3D computation fluid dynamics modelling to predict the air flows around a building with long-term historical wind data, followed by statistical analysis to determine whether future conditions will exceed accepted thresholds, we can inform the design, ideally in its initial stages. Among other things, this enables identification of the optimal location for the building’s entrance and areas for outdoor seating. Alternatively the effects can be mitigated by planting trees or including features such as wind baffles or screens.