The Massachusetts Institute of Technology (MIT), has unveiled its new state of the art wind tunnel, which replaces its 80-year-old predecessor. MIT is now the US’s most advanced wind tunnel and has high hopes for its future.
In 2017, the MIT Department of Aeronautics and Astronautics declared that it would replace the tunnel by a new facility, thanks to a Boeing lead funding commitment. The tunnel is capable of reaching wind speeds of up to 230 mph (370 kph), and it has the largest test section in U.S. academic research.
This upgrade is essential for the institute as the tunnel that was older was very old.
“Decrepit is the best word I could use to describe the tunnel’s condition after 80 years. The tunnel shell, supporting foundations, instrumentation, drive motor, and fan were all in poor condition. The tunnel had poor airflow quality and was very noisy and inefficient,” Mark Drela is the Terry J. Kohler Professor, director of the Wright Brothers Wind Tunnel.
It just wasn’t up to our modern standards for wind tunnel testing. We set out to make our vintage tunnel more modern and relevant for the 21st century. And we succeeded.
What is the purpose of wind tunnels?
Wind tunnels are a common feature of wind tunnels. Orville and Wilbur Wright used one before they flew in 1903. In their simple, open-ended wind tunnel they tested candidates wing designs.
Wind tunnels, which circulate air around stationary objects in controlled settings, are a great tool to collect aerodynamic data. It is crucial to fully understand the aerodynamic forces that are at work when designing an object that interacts with airflow. This will allow you to identify and fix any design flaws.
Wind tunnel measurements can help to predict how much fuel an airplane will consume, how slow it can land and how long it takes to take off. These measurements can be used to monitor wind loads on stationary objects such as bridges and buildings as well as aerodynamic loads of ground vehicles such as cars and bikes.
Engineers and scientists also use wind tunnels for basic research. They are used to study how air reacts with items in order to better understand fluid mechanics.
Modern wind tunnels are designed to produce as clean an airflow as possible. This requires a large cross-section of the wind tunnel. This would require some serious redesigning for the new tunnel.
Like any engineering project, cost and size were important considerations. Drela explains that we couldn’t simply take a traditional tunnel design and make it fit in the tunnel’s small space. We had to think of new ways to do this. He explained that a completely new architecture was needed with numerous innovations in the fan, diffusers and contraction. This would allow the tunnel to achieve the desired capabilities within the existing footprint.
Both the original Wright Brothers tunnels and the new Wright Brothers tunnels have closed circuit designs. Air flows through the test section for measurement purposes, before it recirculates around the tunnel. However, there are no similarities.
The tunnel of the future is completely different
The BLI fan is powered by a 2,500-horsepower motor (1864.25kW), which makes it much simpler than the complex variable pitch drive in the old tunnel. Variable frequency drives control the motor speed, making it more efficient and quieter than old tunnel systems.
The fan presses the tunnel at its maximum speed. This allows the tunnel’s far wall to withstand up to 80 tonnes of load. It is equivalent to a hurricane with a force of 240 mph (386 km/h). Only the fan and the test section of the Wright Brothers Wind Tunnel are attached to the ground in order to resist the elastic flexing.
The tunnel’s remaining supports include sliding and rocking. This allows it to “squirm”, or move up to a centimeter. This relieves major stress from temperature fluctuations and pressure loads.
As its predecessor, the new tunnel will continue to represent AeroAstro at MIT and other public outreach activities. The tunnel was used by other MIT instructors to teach classes and test new equipment with student groups. Visitors can enter the test area to see the wind tunnel at work. The air blows at a breezy 30-mph (48 km/h). This attraction has been popular during school events.