Real-time simulation of a helicopter rotor on an analog computer

Abstract

An accurate real-time simulation of a helicopter rotor can be achieved on a high-speed analog computer. By using repetitive operation and integrating along each blade every 2.5 milliseconds, the double integration required to determine rotor torque, thrust, moment, and rearward and sideward rotor forces is accomplished. The lift and drag coefficients are continuously calculated at all points along the blade. The same analog equipment used to calculate quantities for one blade is used for other blades by chang ing appropriate initial conditions. This analysis provides a transient rotor solution in which integration out the blade is accomplished every five rotor azimuth degrees. One console of a Hybrid Systems, Inc., SS-100 Analog/Hybrid Computer is used for the rotor solution.