scholarly journals Optimization of Engine Model Parameters Gain and Time Constant for the Cessna Citation X Business Aircraft Engine

Author(s):  
Ruxandra Mihaela Botez ◽  
◽  
Julian Anthony ◽  
Clementa Hamel
Author(s):  
Takahisa Kobayashi ◽  
Donald L. Simon

In this paper, a baseline system which utilizes dual-channel sensor measurements for aircraft engine on-line diagnostics is developed. This system is composed of a linear on-board engine model (LOBEM) and fault detection and isolation (FDI) logic. The LOBEM provides the analytical third channel against which the dual-channel measurements are compared. When the discrepancy among the triplex channels exceeds a tolerance level, the FDI logic determines the cause of the discrepancy. Through this approach, the baseline system achieves the following objectives: 1) anomaly detection, 2) component fault detection, and 3) sensor fault detection and isolation. The performance of the baseline system is evaluated in a simulation environment using faults in sensors and components.


Author(s):  
Takahisa Kobayashi ◽  
Donald L. Simon

In this paper, an enhanced on-line diagnostic system which utilizes dual-channel sensor measurements is developed for the aircraft engine application. The enhanced system is composed of a nonlinear on-board engine model (NOBEM), the hybrid Kalman filter (HKF) algorithm, and fault detection and isolation (FDI) logic. The NOBEM provides the analytical third channel against which the dual-channel measurements are compared. The NOBEM is further utilized as part of the HKF algorithm which estimates measured engine parameters. Engine parameters obtained from the dual-channel measurements, the NOBEM, and the HKF are compared against each other. When the discrepancy among the signals exceeds a tolerance level, the FDI logic determines the cause of discrepancy. Through this approach, the enhanced system achieves the following objectives: 1) anomaly detection, 2) component fault detection, and 3) sensor fault detection and isolation. The performance of the enhanced system is evaluated in a simulation environment using faults in sensors and components, and it is compared to an existing baseline system.


Author(s):  
Daniel Viassolo ◽  
Aditya Kumar ◽  
Brent Brunell

This paper introduces an architecture that improves the existing interface between flight control and engine control. The architecture is based on an on-board dynamic engine model, and advanced control and estimation techniques. It utilizes a Tracking Filter (TF) to estimate model parameters and thus allow a nominal model to match any given engine. The TF is combined with an Extended Kalman Filter (EKF) to estimate unmeasured engine states and performance outputs, such as engine thrust and turbine temperatures. These estimated outputs are then used by a Model Predictive Control (MPC), which optimizes engine performance subject to operability constraints. MPC objective and constraints are based on the aircraft operation mode. For steady-state operation, the MPC objective is to minimize fuel consumption. For transient operation, such as idle-to-takeoff, the MPC goal is to track a thrust demand profile, while minimizing turbine temperatures for extended engine time-on-wing. Simulations at different steady-state conditions over the flight envelope show important fuel savings with respect to current control technology. Simulations for a set of usual transient show that the TF/EKF/MPC combination can track a desired transient thrust profile and achieve significant reductions in peak and steady-state turbine gas and metal. These temperature reductions contribute heavily to extend the engine time-on-wing. Results for both steady state and transient operation modes are shown to be robust with respect to engine-engine variability, engine deterioration, and flight envelope operating point conditions. The approach proposed provides a natural framework for optimal accommodation of engine faults through integration with fault detection algorithms followed by update of the engine model and optimization constraints consistent with the fault. This is a potential future work direction.


Author(s):  
Tashfeen Mahmood ◽  
Anthony Jackson ◽  
Vishal Sethi ◽  
Pericles Pilidis

This paper discusses thrust reversing techniques for a separate exhaust high bypass ratio turbofan engine and its effect on aircraft and engine performance. Cranfield University is developing suitable thrust reverser performance models. These thrust reverser performance models will subsequently be integrated within the TERA (Techno-economic Environmental Risk Analysis) architecture thereby allowing for more detailed and accurate representations of aircraft and engine performance during the landing phase of a typical civil aircraft mission. The turbofan engine chosen for this study was CUTS_TF (Cranfield University Twin Spool Turbofan) which is similar to the CFM56-5B4 engine and the information available in the public domain is used for the engine performance analysis along with the Gas Turbine Performance Software, ‘GasTurb 10’ [1]. The CUTEA (Cranfield University Twin Engine Aircraft) which is similar to the Airbus A320 is used alongside with the engine model for the thrust reverser performance calculations. The aim of this research paper is to investigate the effects on aircraft and engine performance characteristics due to the pivoting door type thrust reverser deployment. The paper will look into the overall engine performance characteristics and how the engine components get affected when the thrust reversers come into operation. This includes the changes into the operating point of fan, booster, HP compressor, HP turbine, LP turbine, bypass nozzle and core nozzle. Also, thrust reverser performance analyses were performed (at aircraft/engine system level) by varying the reverser exit area by ± 5% and its effect on aircraft deceleration rate, deceleration time and landing distances were observed.


Author(s):  
R. H. Smith ◽  
J. D. Chisholm ◽  
J. F. Stewart

An adaptive, integrated flight/propulsion control algorithm called Performance Seeking Control (PSC) has been developed to optimize total aircraft performance during steady state engine operation. The multi-mode algorithm will minimize fuel consumption at cruise conditions; maximize excess thrust (thrust minus drag) during aircraft accelerations, climbs, and dashes; and extend engine life by reducing Fan Turbine Inlet Temperature (FTIT) when the extended life mode is engaged. On-board models of the inlet, engine, and nozzle are optimized to compute a set of control trims, which are then applied as increments to the nominal engine and inlet control schedules. The on-board engine model is continually updated to match the operating characteristics of the actual engine cycle through the use of a Kalman filter, which accounts for anomalous engine operation. The PSC algorithm will be flight demonstrated on an F-15 test aircraft under the direction of the NASA Ames/Dryden Flight Research Facility. This paper discusses the PSC design strategy, describes the control algorithm, and presents results from high fidelity, nonlinear aircraft/engine simulations. Simulation results indicate that thrust increases as high as 15% and specific fuel consumption reductions up to 3% are realizable by the PSC system.


Author(s):  
Carlos Xisto ◽  
Fakhre Ali ◽  
Olivier Petit ◽  
Tomas Grönstedt ◽  
Andrew Rolt ◽  
...  

This paper proposes a pulse detonation combustion (PDC) model integrated within Chalmers University’s gas turbine simulation tool GESTPAN (GEneral Stationary and Transient Propulsion ANalsysis). The model will support the development of novel aircraft engine architectures exploiting the synergies between intercooling, aftercooling and PDC. The proposed engine architectures are based on a reference high bypass ratio geared-turbofan engine model with performance levels estimated to be available by year 2050. Parametric studies have been carried out for each proposed advanced architecture, providing engine cycle mid-cruise design point parameters. Design sensitivity studies related to intercooling technology in combination with a PDC are further explored for a number of heat-exchanger design effectiveness values and associated pressure loss levels. The acquired results suggest that the incorporation of PDC technology within a conventional core has the potential to significantly improve engine thermal efficiency. Incorporating intercooling improves the cycle performance for any pre-combustion OPR above 10 and contributes to an increase in specific power over the entire range of OPR. Finally, the results demonstrate that aftercooling the high pressure compressor delivery air further improves core specific power, but cancels out any SFC and thermal efficiency benefits arising from pulse detonation.


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