Since its creation, hang gliding has progressed solely — and often painfully — through experimentation. But engineering simulation is starting to change that.
The German inventor and flight pioneer Otto Lilienthal made over 2,000 flights as long as 820 feet in gliders he designed and flew in the 1890s. He died in 1896 from injuries sustained in a glider crash, but his well-documented accounts of theories and experiences with flight influenced many of the early aviation pioneers, including the Wright Brothers.
In the 1940s, Dr. Francis Rogallo, a scientist at NACA (the forerunner of NASA) and his wife Gertrude developed a self-inflating flexible wing. By the end of the 1950s and beginning of the 1960s, with the space race in full gear and the need of a way to bring space capsules and their occupants safely back to Earth, NASA briefly considered the Rogallo wing, but development problems ultimately forced its replacement with the parachute.
In 1963, an Australian inventor named John Dickenson set out to build a stable and controllable water-ski kite glider by adapting the Rogallo wing airfoil concept with a four-boon stiffened airframe and a swinging seat for the pilot. He used a control frame and wire bracing that distributed the load to the wing, as well as giving a frame to brace for weight-shift control. His creation ultimately prompted the FAI (World Air Sports Federation) to vest him with the invention of the modern hang glider.
Leveraging Simulation for Optimal Design and Performance
Times have changed since then, and now Aerospace Innovations of Canada, as part of the ANSYS Startup Program, is leveraging the easy-to-use but highly sophisticated ANSYS AIM simulation platform for the first computer simulations of a hang glider.
The Hang Glider Manufacturers Association has certification standards that surpass those of regular airplanes – they require tests that are more destructive and way past a normal flight envelope. But now, all conditions can be checked even before the first part is manufactured, not only with ANSYS computational fluid dynamics (CFD) simulations, but also with finite element analysis. With this combined method, we can analyze the flight characteristics and material stress safety margins all at once. The goal of this comprehensive analysis is to give the sport of hang gliding a quantum leap in performance, weight reduction and assembly time — parameters that have proven to be the most challenging for hang gliding enthusiasts.
To help us reach this demanding target, we are also leveraging more recent NASA research into a glider called Prandtl-D. NASA’s experiments have shown that its bell lift distribution enables improved aircraft designs, particularly for all flying-wing aircraft and blended-wing body aircraft.
The bell span load maximizes aerodynamic efficiency for a given structure, and coordinates the roll-yaw motion that enables birds to turn and maneuver without a vertical tail. It also explains why birds fly in formations with their wingtips overlapped, and how birds can have such narrow wingtips without experiencing tip stall. Also, this bell lift distribution diminishes the load near the wing tips, allowing for a much simpler wing structure, which reduces the weight and complexity of the structure.
With the help of ANSYS Startup Program, we at Aerospace Innovations of Canada are developing a prototype to propel the next generation of extreme sports into the sky.