The main developer of HELI-X holds a PhD in applied mathematics and is an expert in computational fluid dynamics. He worked successfully on many projects in aerodynamics. He is not only pilot of R/C helicopters but also a privat pilot of airplanes. He says: « Of course there are many books and publications on helicopter aerodynamics and flight simulation available. However, the helicopter aerodynamics described in these publications mainly deal with the stationary situation and are in a Reynolds number regime which is different to what is of interest for R/C helicopters. But even more important, the flight dynamics of R/C helicopters is much more complex than that of the full size helicopters, so that particular models had to be built. In fact, the physics engine of HELI-X is written from scratch. Another important feature of HELI-X is that also the flow outside of the helicopter is modelled which e.g. enables a realistic behavior in auto rotations or the spin up of the rotors. “

Besides others, the following effects are modelled in HELI-X:

  • Transitional lift
  • Stall
  • Ground Effect
  • Dynamic Stall
  • Vortex Ring State
  • Boundary layer separation at the Blades
  • Paddle dynamics
  • Rotor head stiffness
  • Nick/roll coupling