Scott Graham, Ivan Wong, Won-Zon Chen, Alex Lazarevic, Keith Cleek, Northrop Grumman Corporation ; E. A. Walters, C. E. Lucas, O. Wasynczuk PC Krause and Associates, Inc; Peter Lamm, U.S. Air Force Research Laboratory
Future Air Force intelligence, surveillance, and reconnaissance (ISR) platforms, such as high-altitude Uninhabited Aerial Vehicles (UAV), may drastically change the requirements of aircraft power systems. For example, there are potential interactions between large pulsed-power payloads and the turbine engine that could compromise the operation of the power system within certain flight envelopes. Until now, the development of large-scale, multi-disciplinary (propulsion, electrical, mechanical, hydraulic, thermal, etc.) simulations to investigate such interactions has been prohibitive due to the size of the system and the computational power required. Moreover, the subsystem simulations that are developed separately often are written in different commercial-off-the-shelf simulation programs. In this paper, a new technique useful for the numerical simulation of large-scale systems to overcome these obstacles, known as Distributed Heterogeneous Simulation (DHS), is utilized to form a dynamic system-level simulation of a high-altitude, long-endurance UAV-type of power system. This system includes detailed dynamic models of a turbine engine, high- and low-spool generators, and payloads. Although not necessary, all of the component models for this system were developed within the same simulation environment, specifically with MATLAB/Simulink. This enabled a single-computer integrated system model and a distributed computer system simulation to be formed thereby allowing for a direct comparison of simulation accuracy and computational performance for the two simulation approaches. From this comparison, it was determined that by distributing the system simulation across three computers, a 21-fold increase in simulation speed could be realized while producing nearly identical results.
2004 SAE Power Systems Conference, November 2-4, 2004 Paper #2004-01-3193 and Aerospace Engineering, November 2004, pp. 24–27.