Published on March 20th, 2012 | by Joshua S Hill0
Could a Biplane Bring Back Commercial Supersonic Travel?
Ever since the Concorde was retired from service at the end of 2003, we haven’t had commercial supersonic travel available, but researchers who have been studying the problems of supersonic travel believe they may have found the answer — a biplane.
Qiqi Wang, an assistant professor of aeronautics and astronautics at MIT, believes that, in principle, a biplane may solve many of the problems the Concorde suffered from, including the amount of fuel needed, limited seating, and the ever annoying sonic boom that comes when an object reaches Mach 1, or supersonic flight.
“The sonic boom is really the shock waves created by the supersonic airplanes, propagated to the ground,” Wang says. “It’s like hearing gunfire. It’s so annoying that supersonic jets were not allowed to fly over land.”
Working with Rui Hu, a postdoc in the Department of Aeronautics and Astronautics, and Antony Jameson, a professor of engineering at Stanford University, Wang has shown, using a computer model, that a modified biplane could in fact significantly lessen the drag on the plane when compared to a single-wing aircraft traveling at supersonic speeds, which Wang believes would mean the plane would require less fuel to fly and would produce a smaller sonic boom.
“If you think about it, when you take off, not only do you have to carry the passengers, but also the fuel, and if you can reduce the fuel burn, you can reduce how much fuel you need to carry, which in turn reduces the size of the structure you need to carry the fuel,” Wang says. “It’s kind of a chain reaction.”
Wang designed a jet with two wings — one positioned above the other — based on an idea by German engineer Adolf Busemann, who came up with a biplane design in the 1950s that essentially eliminates the shock waves when traveling at supersonic speeds. However, Wang’s specific design had one significant flaw — the design would have worked wonderfully at supersonic speeds, but it would not actually ever be able to reach those speeds due to the wing design.
To address this issue, Wang worked with his colleagues to design a computer model to simulate the performance of the biplane design. They then smoothed out the inner surface of each wing slightly, creating a wider channel through which air could flow, and then bumped out the top edge of the higher wing and the bottom edge of the lower wing.
When they ran their simulations again, they found that this conceptual plane was able to fly at supersonic speeds with half the drag of conventional supersonic jets — like the Concorde — and would actually be able to reach those speeds.
Next on their to-do list is to create a three-dimensional model that will allow them to account for other factors that affect flight.
Image Source: Christine Daniloff/MIT News, based on an original drawing courtesy of Obayashi laboratory, Tohoku University