The Commercial Modular Aero-Propulsion System Simulation 40k (C-MAPSS40k) software package is a nonlinear dynamic simulation of a 40,000-pound (≈178-kN) thrust class commercial turbofan engine, written in the MAT-LAB/Simulink environment. The model has been tuned to capture the behavior of flight test data, and is capable of running at any point in the flight envelope [up to 40,000 ft (≈12,200 m) and Mach 0.8]. In addition to the open-loop engine, the simulation includes a controller whose architecture is representative of that found in industry.

The simulation environment gives the user easy access to health, control, and engine parameters. C-MAPSS40k has a graphical user interface (GUI) to allow users to easily specify an arbitrarily complex flight profile to be simulated, as well as ambient conditions and deterioration level of the engine. C-MAPSS40k has three actuators: fuel flow, variable stator vanes, and variable bleed valve. The three actuators enable off-nominal operation, which is not possible with simulations that have fuel flow as the sole actuator, since in those simulations the other actuators are implicit and assumed to operate nominally. The simulation is modular to allow users to redesign or replace components such as the engine controller or turbomachinery components without having to modify the rest of the simulation. It also enables the user to view and save any signal in the engine or controller. The package has the capability to create and validate a linear model of the engine at any operating point. Linear models can be used for control design, and C-MAPSS40k lends itself well to implementation and evaluation of advanced control designs as well as to diagnostic and prognostic system development. The simulation can be run in real time and can therefore be integrated into a flight simulator with a pilot in the loop for testing.

C-MAPSS40k fills the need for an easy-to-use, realistic, transient simulation of a medium-size commercial turbofan engine with a representative controller. It is a detailed component level model (CLM) written in the industry-standard graphical MATLAB/Simulink environment to allow for easy modification and portability. At the time of this reporting, no other such model exists in the public domain.

This work was done by Ten-Huei Guo, Thomas Lavelle, and Jonathan Litt of Glenn Research Center and Jeffrey Csank of N&R Engineering and Ryan May of ASRC.

Inquiries concerning rights for the commercial use of this invention should be addressed to NASA Glenn Research Center, Innovative Partnerships Office, Attn: Steven Fedor, Mail Stop 4–8, 21000 Brookpark Road, Cleveland, Ohio 44135. Refer to LEW-18624-1.