Experimental Evaluation of a Flat Wake Theory for Predicting Rotor Inflow-Wake Velocities
Abstract
The theory for predicting helicopter inflow-wake velocities called flat wake theory was correlated with several sets of experimental data. The theory was developed by V. E. Baskin of the USSR, and a computer code known as DOWN was developed at Princeton University to implement the theory. The theory treats the wake geometry as rigid without interaction between induced velocities and wake structure. The wake structure is assumed to be a flat sheet of vorticity composed of trailing elements whose strength depends on the azimuthal and radial distributions of circulation on a rotor blade. The code predicts the three orthogonal components of flow velocity in the field surrounding the rotor. The predictions can be utilized in rotor performance and helicopter real-time flight-path simulation. The predictive capability of the coded version of the theory was correlated with flow velocity data from several sources. In general, the coded version of flat wake theory provides vertical inflow patterns similar to experimental patterns.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1992
- Accession Number
- ADA250192
Entities
People
- John C. Wilson
Organizations
- United States Army Aviation and Missile Command