Download Free Development And Validation Of A Civil Aircraft Engine Simulation Model For Advanced Controller Design Book in PDF and EPUB Free Download. You can read online Development And Validation Of A Civil Aircraft Engine Simulation Model For Advanced Controller Design and write the review.

This thesis is concerned with the results of a joint academic and industrial study on the development of a detailed nonlinear dynamic model of a turbofan jet engine to be used for research into advanced control strategies for civil turbofan aircraft engines. The model is representative of a dual shaft engine with variable bleed, variable stator vanes, turbine cooling, heat transfer, and a duct and exhaust nozzle. A switched, gain-scheduled, feedback control system incorporating bumpless transfer and antiwindup functionality has been designed and implemented according to current industrial practice. This baseline implementation permits realistic transient operation of the simulation and may act as a reference design for further control work. The simulation computes a non-iterative solution, by progressing calculations in the direction of the gas stream flow. Where possible the underlying physics are used and empirical approximations are avoided so that the model requires minimum data. This approach also makes a future inclusion of component failure easier to implement. The simulation is modular in nature so that engine or control modules can be easily replaced or modified if an improved design becomes available. The Simulink implementation of the control architecture has been redesigned to permit the addition or removal of control loops, also during the simulation?s operation, to allow testing of advanced control strategies. The entire controller can also be easily replaced. A detailed description of the modeling process, the various simulation issues that arise with a model of this complexity, and the results of the overall aero-engine system are presented. The design of the switched, gain-scheduled aero-engine controller with bumpless transfer and antiwindup which achieves dynamic performance that closely matches that of a real aero-engine is also discussed.
This book aims to develop systematic design methodologies to model-based nonlinear control of aeroengines, focusing on (1) modelling of aeroengine systems—both component-level and identification-based models will be extensively studied and compared; and (2) advanced nonlinear control designs—set-point control, transient control and limit-protection control approaches will all be investigated. The model-based design has been one of the pivotal technologies to advanced control and health management of propulsion systems. It can fulfil advanced designs such as fault-tolerant control, engine modes control and direct thrust control. As a consequence, model-based design has become an important research area in the field of aeroengines due to its theoretical interests and engineering significance. One of the central issues in model-based controls is the tackling of nonlinearities. There are publications concerning with either nonlinear modelling or nonlinear controls; yet, they are scattered throughout the literature. It is time to provide a comprehensive summary of model-based nonlinear controls. Consequently, a series of important results are obtained and a systematic design methodology is developed which provides consistently enhanced performance over a large flight/operational envelope, and it is thus expected to provide useful guidance to practical engineering in aeroengine industry and research.
Designing modern aircraft is not an easy task. Today, it is not enough to optimize aircraft sub-systems at a sub-system level. Instead, a holistic approach is taken whereby the constituent sub-systems need to be designed for the best joint performance. The State-of-the-Art (SotA) in simulating and exchanging simulation models is moving forward at a fast pace. As such, the feasible use of simulation models has increased and additional benefits can be exploited, such as analysing coupled sub-systems in simulators. Furthermore, if aircraft sub-system simulation models are to be utilized to their fullest extent, opensource tooling and the use of open standards, interoperability between domain specific modeling tools, alongside robust and automated processes for model Verification and Validation (V&V) are required. The financial and safety related risks associated with aircraft development and operation require well founded design and operational decisions. If those decisions are to be founded upon information provided by models and simulators, then the credibility of that information needs to be assessed and communicated. Today, the large number of sensors available in modern aircraft enable model validation and credibility assessment on a different scale than what has been possible up to this point. This thesis aims to identify and address challenges to allow for automated, independent, and objective methods of integrating sub-system models into simulators while assessing and conveying the constituent models aggregated credibility. The results of the work include a proposed method for presenting the individual models’ aggregated credibility in a simulator. As the communicated credibility of simulators here relies on the credibility of each included model, the assembly procedure itself cannot introduce unknown discrepancies with respect to the System of Interest (SoI). Available methods for the accurate simulation of coupled models are therefore exploited and tailored to the applications of aircraft development under consideration. Finally, a framework for automated model validation is outlined, supporting on-line simulator credibility assessment according to the presented proposed method.
A new high-fidelity simulation of a generic 40,000 lb thrust class commercial turbofan engine with a representative controller, known as C-MAPSS40k, has been developed. Based on dynamic flight test data of a highly instrumented engine and previous engine simulations developed at NASA Glenn Research Center, this non-proprietary simulation was created especially for use in the development of new engine control strategies. C-MAPSS40k is a highly detailed, component-level engine model written in MATLAB/Simulink (The MathWorks, Inc.). Because the model is built in Simulink, users have the ability to use any of the MATLAB tools for analysis and control system design. The engine components are modeled in C-code, which is then compiled to allow faster-than-real-time execution. The engine controller is based on common industry architecture and techniques to produce realistic closed-loop transient responses while ensuring that no safety or operability limits are violated. A significant feature not found in other non-proprietary models is the inclusion of transient stall margin debits. These debits provide an accurate accounting of the compressor surge margin, which is critical in the design of an engine controller. This paper discusses the development, characteristics, and capabilities of the C MAPSS40k simulation.
Overview of engine control systems -- Engine modeling and simulation -- Model reduction and dynamic analysis -- Design of set-point controllers -- Design of transient and limit controllers -- Control system integration -- Advanced control concepts -- Engine monitoring and health management -- Integrated control and health monitoring -- Appendix A. Fundamentals of automatic control systems -- Appendix B. Gas turbine engine performance and operability.