It was 8-year-old Joshua Prabahar's Kitty Hawk moment, accomplished not on an isolated strip of beach in North Carolina but in a Kingston, Jamaica, home, where toilet paper tubes, cardboard, and masking tape served as the parts for his Wright brothers-inspired toy airplanes.
And like Wilbur and Orville, who made a multitude of adjustments to their engine-powered 1903 Wright Flyer, Prabahar tinkered endlessly with his creations, bending and folding the wings so that the aircraft could gain altitude faster.
Prabahar may not have realized it, but he was on the right track: The key to accomplishing greater lift is in the wings' angle of attack.
Today, as an aeronautical engineering major at the University of Miami, he is still experimenting with techniques to build a better airplane—only now, the materials and methods he employs are much more advanced: 3D-printed plastic parts and an airflow simulator.
Prabahar has designed and built a prototype airfoil that uses what he describes as "suction and injection" along the wing's surface to create lift. "We've done baseline computer simulations to prove that our concept is feasible, and it's shown promising results in that regard," he said. "Now, we've moved to wind tunnel testing to demonstrate that our design can achieve enhanced aerodynamic performance."
Designed through the process of computational fluid dynamics, the airfoil would serve as the wing of an electric short takeoff or landing (STOL) aircraft, with the real-world benefits from such technology resulting in flying machines that would deliver medicine and other essential goods to hard-to-reach areas, make aerial damage assessments in the aftermath of hurricanes and other natural disasters, and transport patients to medical facilities.
Prabahar's airfoil had its origins in his College of Engineering senior design project. With funding for that task capped at $250, he and his team knew they couldn't afford to design, create, and test a new airfoil and considered building a remote-control airplane instead.
"But it was our dream to aggressively pursue and test our design theories for a new type of wing," he said, "and we were determined to see it through."
The college's new Miami Engineering Autonomous Mobility Initiative, a consortium dedicated to developing electric vertical takeoff and landing (eVTOL) aircraft, came to the rescue, allocating additional funds that allowed Prabahar and his team to take their airfoil design from concept to creation.
But even before wind tunnel testing could begin, Prabahar and his team had to overcome a final obstacle: adapting the airflow simulator to test a 3D-printed plastic component, as it had originally been constructed to assess the performance of metal and aluminum parts.
"We had to take numerous measurements and check that all the alignments were just right," Prabahar recalled. "Without a doubt, it was the biggest design issue we faced."
STOL and eVTOL aircraft are the future, he asserts.
"Increasing the range of such vehicles through better electric batteries is the next challenge," he said. "But it's sustainable, clean, and quiet technology—way above the toy airplanes I used to build as a little boy."
