Wind Tunnel Hall
Specially designed facilities for experimental investigations of the aerodynamics of a wide range of objects, including sails, wings, cyclists, vehicles, flags, buildings, towers and roofs.
Our two wind tunnels provide our staff and students with unique opportunities to commence with a wide range of innovative research and testing. These wind tunnels are also available for contract research. Find out more about the testing capabilities on the Wind Tunnel Hall website.
Boundary Layer Wind Tunnel
The Boundary Layer Wind Tunnel – the largest and fastest of its kind in New Zealand – was constructed at the Newmarket Campus in 2015. Its test section is 20 m long, 3.6 m wide and 2.5 m high, and it has a top speed of 20 m/s. It is designed as a general purpose wind tunnel and has facilities for testing model buildings in wind engineering studies, the drag and power of cyclists on a special balance/dynamometer, and model vehicles on a moving belt ground plane. It may also be used for measuring the drag of bodies like traffic signs, and the loads and performance of wind turbines.
For Wind Engineering studies, its long test section enables the wind simulation to be controlled so that a range of scales from 1:100 to 1:600 can be used, and it can simulate the flow above smooth surfaces like water to rough surfaces like cities by suitable combinations of blocks, barriers and spires. Coupled with the 512-channel high frequency pressure system, and several sensitive high frequency force balances, it is a powerful facility for investigating loads, pressures and vibrations on models of buildings and other structures like stadium roofs.
Twisted Flow Wind Tunnel
Our primary facility for sail testing is the Twisted Flow Wind Tunnel, which is a large open circuit wind tunnel with a straight duct 20 m long. Blocks and barriers of different sizes may be placed on the floor to control the wind speed and turbulence variation with height of the flow onto the model. The wind tunnel has helped several America's Cup and Volvo 70 designers produce winning designs as it is has special vertical twisting vanes at the duct outlet enabling the direction of the flow in the test section to be varied in a controlled manner with height. In this way the "apparent" wind speed and direction onto the sails which varies with height when a yacht sails through the wind, can be simulated in a wind tunnel test on a stationary model. In its yacht-sail testing configuration, the wind tunnel test section is 7 m wide and 3.5 m high, and has a top speed of 8 m/s. The vanes can be removed and the walls of the wind tunnel duct contoured to give narrower outlets for testing smaller objects at greater speeds. The 3.5 m x 3.5 m square outlet can be used for testing small wind turbines, model vehicles and tall buildings. The 2.5m wide x 3.5 m high outlet is used for tests where higher speeds are required, and in this configuration the top speed is 60 km/h.
R. G. J. Flay (1996). A Twisted Flow Wind Tunnel for Testing Yacht Sails. J Wind Eng. & Ind. Aerodyn, 63. 171-182.