Unsteady Separated Flows on Rotor-Airfoils - Analysis and Visualization of Numerical Data -

Abstract

Unsteady viscous flows with separation may be dominant on retreating rotor blades of helicopters in forward flight. These flows are investigated by a time-accurate numerical solution of the 2d-Navier-Stokes equations on deformable meshes. Lift and moment characteristics are compared with experimental data. Compressibility effects are found to be of considerable importance with respect to the development of the dynamic stall process. Large sets of field data (i.e. pressure, density, velocities, vorticity, etc.) are available to investigate the details of the flow. Suitable visualization techniques are necessary to sufficientlyinterpret these data. Pseudo 3d-viewing of the 2d-unsteady data as well as the medium: video movie serve as effective tools for phyical interpretation and understanding of the unsteady separated flow fields.