A Supersonic Biplane
In 2003, the Concorde—the supersonic jet that ferried passengers from New York to Paris in three and a half hours—retired from service following years in which it was criticized for expensive tickets, high fuel costs, and noise disruption from the jet’s sonic boom.
Now researchers from MIT and Stanford University have come up with a concept that may solve many of the problems that grounded the Concorde. Qiqi Wang, an assistant professor of aeronautics and astronautics, says the solution, in principle, is simple: instead of flying with one wing to a side, why not two?
Wang says a jet with two wings—one positioned above the other—would cancel out the shock waves produced by either wing alone, minimizing sonic booms. The design could also halve the amount of fuel required to fly the plane.
Wang credits German engineer Adolf Busemann for the original design. In the 1950s, Busemann conceptualized a biplane that would essentially eliminate shock waves at supersonic speeds. But the design would produce so much drag as the plane neared Mach 1 that it would never reach supersonic speeds.
Wang’s group designed a computer model to simulate the performance of Busemann’s biplane, determining the best wing shape to minimize drag at various speeds. The researchers aggregated the results from different speeds and wing configurations to come up with an optimal shape for each wing.
They found that by rounding out the top edge of the higher wing and the bottom edge of the lower wing, they could get the conceptual plane to fly at supersonic speeds, with half the drag of conventional supersonic jets such as the Concorde.
“Now people are having more ideas on how to improve [Busemann’s] design,” Wang says. “There may be a boom in the field in the coming years.”