A procedure for establishing an approximate helicopter performance model

The main performance characteristics of a helicopter is its fuel consumption. This paper reports the current state in an ongoing project seeking a fast and approximative implementation of mathematical models for helicopter performance predictions, primarily in terms of fuel consumption. The model is limited to a subset of the normal operation modes, only including hover, climb and forward. Also, the focus is on smaller rotors, i.e. sub-scale rotors in the range of 1.5m to 4.0m in diameter as used in unmanned airborne vehicles (VTOL-UAV). The presented work consists of three parts; the helicopter performance mathematical model and the numerical optimization method used for dealing with its implicit nature, the approximation grid scheme and the simulation of flight paths. The overall objective of the project is to establish an computational efficient approximative model usable for onboard condition monitoring of the helicopter performance and fuel consumption.