CFD – a key element of helicopter activities at the IAG

Helicopter flow computation is still a challenging task these days. The flow is instationary and transonic in a complex, time varying geometry and thus very difficult to simulate accurately. Besides that, reliable results can be achieved only if the dynamics of the blade are taken into account as well. Even in hover, but more so in forward flight the aerodynamic problem is tightly coupled to the structural response of the blades to aerodynamic forces. Rigid body motions occur as well as elastic deformations like bending and especially twist. In addition to the aerodynamic performance of a helicopter, acoustical effects become an important issue more and more. Consequently aeroacoustic data has to be generated as well as aerodynamic and aeroelastic. Realistic helicopter rotor simulations are therefore a multi disciplinary problem, where computational fluid dynamics admittedly plays the key role.