Coanda Effect Inspired Youthful Winner of Sikorsky Challenge
The Coanda effect, which is central to the performance of the MD Helicopters Notar (no tail rotor) and the tail-boom strakes on many other helicopters, inspired 16-year-old Ethan Chu’s design for a helicopter that won him the Igor Sikorsky Youth Innovator Award in the second annual Helicopter 2050 Challenge (http://www.helicopter2050.com).
“I was fascinated with the Coanda effect,” Chu said, “and I decided to use it to make my helicopter design more efficient.”
The competition challenged youth, ages 9 to 16 years, to envision an environmentally friendly helicopter, with judges rating the designs for concept uniqueness, description detail and creativity of the presentation. Chu’s design describes a compact, twin-engine helicopter intended for medical evacuation.
The dome-shaped helicopter, which Chu calls the AH-9 Diamondback, incorporates a high-strength structure, featuring lightweight carbon nanotubes covered with titanium panels, an approach that reduces the helicopter’s weight and fuel consumption while increasing its carrying capacity. Two turbofan engines would power a four-blade main rotor. The rotor blades would have symmetrical airfoil cross-sections, providing less drag. Two stub wings under the cockpit would enhance control and stability at high speed.
By channeling engine exhaust along the rotor blades and around the fuselage, Chu’s helicopter would use the Coanda effect to provide a cushion of gas for additional lift, further reducing the Diamondback’s carbon footprint. A fan would push the air down and out at high speed around the body, creating a low-pressure area around the top of the helicopter, which then creates extra lift. The design also includes space for a medic and two patients.
“We were impressed with the strong scientific reasoning and the good deal of thought that Ethan put into his innovative submission,” said Vern Van Fleet, a chief test engineer for Sikorsky Military Systems. “And he never lost sight of the competition theme, which was to produce an environmentally friendly helicopter.”
Chu, an 11th grader who plans to be an aerospace engineer, is a member of the Eta Sigma Alpha National Home School Honor Society at his high school in South Bend, Ind. “This competition gave me the opportunity to learn new knowledge and gain new skills,” he said.
Chu’s award included a trophy, $1,000 and trip to Sikorsky’s headquarters in Stratford, Conn. During their visit to Sikorsky, Chu and his father toured the Black Hawk and Seahawk assembly lines and met company rotorcraft designers and engineers.
Sikorsky Aircraft, a division of United Technologies, and By Kids For Kids, an organization that inspires youth invention, innovation and entrepreneurship, sponsor the Helicopter 2050 competition and announced Chu, as the grand-prize winner, and the four other finalists in December.