Supertall skyscrapers present significant aerodynamic challenges. As structural heights exceed 300 meters, lateral wind loads become the primary design constraint, far exceeding gravity load structural sizing constraints.
Vortex shedding is a primary concern. When strong winds strike a tall rectangular block, they create alternating low-pressure vortices on the sides. These vortices generate crosswind force oscillations, causing lateral structure sway.
To mitigate this vortex shedding, structural engineers employ geometric modifications. Curved facade chamfers, openings, or tapering skyscrapers help disrupt wind streams. In our Helix Tower design, we simulated aerodynamic parameters inside computational fluid dynamics (CFD) engines to optimize the facade's twist rate, reducing lateral stresses by 18%.
Additionally, we detail outrigger belts and install Tuned Mass Dampers (TMD). A TMD consists of a massive concrete or steel ball suspended by steel cables in the upper penthouse. When wind sways the skyscraper in one direction, the TMD sways in the opposite direction, absorbing structural energy and reducing oscillation amplitudes.