Aerostat for the Commonwealth Games

The opening ceremony of the 2010 Commonwealth Games in Delhi had at its centrepiece the world’s largest helium-filled aerostat. We were asked to assess the likely aerodynamic loads on the aerostat to ensure that it could be deployed safely.

During initial design development, we provided guidance on overall aerostat size and weight, working closely with structural engineers given the coupling of aerodynamics, buoyancy, and structural mass.

We used 3-D time-dependent simulation to evaluate the loads on the aerostat, under wind conditions typical of Delhi in September.

Critically, the aerostat must be restrained from moving excessively and the static aerodynamic loads were used to design suitable restraint systems. We were also concerned with time-dependent effects such as bluff body wake shedding; this was analysed and mitigation solutions were incorporated into the final design.

We made recommendations on the maximum wind speed the aerostat could be safely deployed in, and the maximum height the aerostat could rise to while still benefiting from the shading effect of the surrounding stadium.

Chairman of the Organising Committee for the Commonwealth Games 2010, Suresh Kalamadi, MP, described it like this: “The aerostat is no ordinary balloon but a piece of technology, a piece of art.” Kalamadi predicted, “It will add much value to the ceremonies.”