Fluidics in Aircraft Engine Controls

1981 ◽  
Vol 103 (4) ◽  
pp. 324-330 ◽  
Author(s):  
G. E. Davies
Keyword(s):  
Pressure Ratio ◽  
Engine Performance ◽  
Aircraft Engine ◽  
Appropriate Technology ◽  
Engine Fuel ◽  
Engine Control System ◽  
Fuel Flow ◽  
Basic Engine ◽  
Wide Range ◽  
Compressor Inlet

Fluidics is a particularly appropriate technology for engine controls as it is capable of measuring pressure ratio, one of the basic engine performance parameters, as a fundamental quantity. This results in improved accuracy of measurement and obviates the need of conventional systems to utilize nonoptimum, but easier to measure, control parameters. A wide range of aircraft engine controls has been developed covering controls for compressor inlet guide vanes, compressor bleed valves, engine fuel flow including engine instrumentation. Total fluidic unit deliveries exceed 4200 and the civil operating hours exceed 13.5 million. As a further development, a completely fluidic engine control system is proposed with an electronic computer controlled secondary control or trim system for efficiency optimization.

Development of HIDEC Adaptive Engine Control Systems

1987 ◽  
Vol 109 (2) ◽  
pp. 146-151
Author(s):  
R. J. Landy ◽  
W. A. Yonke ◽  
J. F. Stewart
Keyword(s):  
Integrated Control ◽  
Engine Performance ◽  
Control Mode ◽  
Engine Control ◽  
Engine Model ◽  
Engine Control System ◽  
Fuel Flow ◽  
Expected Performance ◽  
Propulsion Control ◽  
And Performance

The NASA Ames/Dryden Flight Research Facility is sponsoring a flight research program designated Highly Integrated Digital Electronic Control (HIDEC), whose purpose is to develop integrated flight-propulsion control modes and evaluate their benefits in flight on NASA F-15 test aircraft. The Adaptive Engine Control System (ADECS I) is one phase of the HIDEC program. ADECS I involves uptrimming the P&W Engine Model Derivative (EMD) PW1128 engines to operate at higher engine pressure ratios (EPR) and produce more thrust. In a follow-on phase, called ADECS II, a constant thrust mode will be developed which will significantly reduce turbine operating temperatures and improve thrust specific fuel consumption. A performance seeking control mode is scheduled to be developed. This mode features an onboard model of the engine that will be updated to reflect actual engine performance, accounting for deterioration and manufacturing differences. The onboard engine model, together with inlet and nozzle models, are used to determine optimum control settings for the engine, inlet, and nozzle that will maximize thrust at power settings of intermediate and above and minimize fuel flow at cruise. The HIDEC program phases are described in this paper with particular emphasis on the ADECS I system and its expected performance benefits. The ADECS II and performance seeking control concepts and the plans for implementing these modes in a flight demonstration test aircraft are also described. The potential payoffs for these HIDEC modes as well as other integrated control modes are also discussed.

Data-Driven Modeling of Aircraft Engine Fuel Burn in Climb Out and Approach

2018 ◽  
Vol 2672 (29) ◽  
pp. 1-11 ◽  
Author(s):  
Yashovardhan S. Chati ◽  
Hamsa Balakrishnan
Keyword(s):  
Model Development ◽  
Gaussian Process Regression ◽  
Ground Truth ◽  
Aircraft Engine ◽  
Engine Fuel ◽  
Fuel Flow ◽  
Fuel Burn ◽  
Aircraft Performance ◽  
Aircraft Trajectory ◽  
Data Driven Modeling

Fuel burn is a key driver of aircraft performance, and contributes to airline costs and emissions. Low-altitude fuel burn and emissions, such as those that occur during climb out and approach, have a significant impact on the environment in the vicinity of airports. This paper proposes a new methodology to statistically model fuel burn in the climb out and approach phases using the trajectory of an aircraft. The model features are chosen by leveraging a physical understanding of aircraft and engine dynamics. Model development is conducted through the use of Gaussian Process Regression on a limited Flight Data Recorder archive, which also provides ground truth estimates of the fuel flow rate and total fuel burn. The result is a class of models that provide predictive distributions of the fuel burn corresponding to a given aircraft trajectory, thereby also quantifying the uncertainty in the predictions. The performance of the proposed models is compared with other frequently used Aircraft Performance Models. The statistical models are found to reduce the error in the estimated total fuel burn by more than 73% in climb out and by 59% in approach.

Paper 2: Similarity Considerations in Assessing Diesel Engine Fuel Spray Requirements

1965 ◽  
Vol 180 (14) ◽  
pp. 10-29 ◽  
Author(s):  
B. E. Knight
Keyword(s):  
Diesel Engine ◽  
Fuel Injection ◽  
Engine Performance ◽  
Fuel Spray ◽  
Theoretical Expression ◽  
Engine Fuel ◽  
Wide Range ◽  
Air Mixing ◽  
Dimensionless Variables ◽  
Mixing Problem

A simplified dimensional analysis has been made of the fuel-air mixing problem in diesel engines. The dimensionless variables describing the mixing pattern have been expressed in terms of the dimensionless variables describing the engine and fuel injection conditions by means of explicit equations with numerical values for the constants. A wide range of such equations has been derived and tables of numerical values are given as examples, together with examples of engine air motion calculations for comparison. A theoretical expression for fuel-spray penetration into a cross-wind has been compared with a few experimental results. Engine smoke and specific consumption measurements have been plotted against the appropriate dimensionless variables in two instances. In both instances the response of the engine to the variables is quite different. It is believed that the wide range of methods of engine performance data analysis outlined in this paper will make a significant contribution to progress in understanding diesel engine combustion.

Multiphysics Numerical Investigation of an Aeronautical Lean Burn Combustor

2019 ◽  
Author(s):  
D. Bertini ◽  
L. Mazzei ◽  
A. Andreini ◽  
B. Facchini
Keyword(s):  
Fluid Dynamics ◽  
Pressure Ratio ◽  
Computational Cost ◽  
Engine Performance ◽  
Pollutant Emissions ◽  
Strong Interactions ◽  
Inlet Temperature ◽  
Test Case ◽  
Lean Burn ◽  
Wide Range

Abstract The importance of the combustion chamber has been underestimated for years by aeroengine manufacturers that focused their research efforts mainly on other components, such as compressor and turbine, to improve the engine performance. Nevertheless, stricter requirements on pollutant emissions have contributed to increase the interest on combustor development and, nowadays, new design concepts are widely investigated. To meet the goals of ACARE FlightPath 2050 and future ICAO-CAEP standards one of the most promising results is provided by the Lean Burn technology. As this combustion mode is based on a lean Primary Zone, the air devoted to liner cooling is restricted and advanced cooling systems must be exploited to obtain higher overall effectiveness. The pushing trends of Turbine Inlet Temperature and Overall Pressure Ratio in modern aeroengine are not supported enough by the development of materials, thus making the research branch of liner cooling increasingly relevant. In this context, Computational Fluid Dynamics is able to predict the flow field and the complex interactions between the involved phenomena, supporting the design of modern Lean Burn combustors in all stages of the process. RANS approaches provide a solution of the problem with low computational cost, but can lack in accuracy when the flow unsteadiness dominates the fluid dynamics and the strong interactions, as in aeroengine combustors. Even if steady simulations can be easily employed in the preliminary design, their inaccuracy can be detrimental for an optimized combustor design and Scale-Resolving methods should be preferred, at least, in the final stages. Unfortunately, having to deal with a multiphysics problem as Conjugate Heat Transfer (CHT) in presence of radiation, these simulations can become computationally expensive and some numerical treatments are required to handle the wide range of time and space scales in an unsteady framework. In the present work the metal temperature distribution is investigated from a numerical perspective on a full annular aeronautical lean burn combustor operated at real conditions. For this purpose, the U-THERM3D multiphysics tool was developed in ANSYS Fluent and applied on the test case. The results are compared against RANS and experimental data to assess the tool capability to handle the CHT problem in the context of scale-resolving simulations.

Development of the Dresser Waukesha 16V150LTD Engine for Bio-Gas Fuels

2009 ◽  
Author(s):  
Edward Reinbold ◽  
James von der Ehe
Keyword(s):  
Engine Performance ◽  
Engine Fuel ◽  
Test Results ◽  
Fuel System ◽  
Heating Value ◽  
Performance Requirements ◽  
Fuel Flow ◽  
Lower Heating Value ◽  
Value Range ◽  
Range Test

Dresser Waukesha released the 16V150LTD engine for operation on pipeline natural gas in 2006. The engine has since been developed for operation on low Btu Bio gas fuels; including landfill and digester applications for both 50 and 60 Hz operation. This paper discusses the development of the engine fuel system, calibration changes, and test results of the Bio-gas 16V150LTD. Fuel system modifications were made for the higher fuel flow rates and calibration changes were necessary to meet performance requirements across the heating value range. Test results are presented which discuss the effects of the lower heating value bio-gas fuels on combustion and engine performance.

scholarly journals Aircraft Gas Turbine Engine Health Monitoring System by Real Flight Data

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Mustagime Tülin Yildirim ◽  
Bülent Kurt
Keyword(s):  
Gas Turbine ◽  
Engine Performance ◽  
Aircraft Engine ◽  
Gas Turbine Engine ◽  
Gas Temperature ◽  
Turbine Engine ◽  
Fuel Flow ◽  
The Status ◽  
Performance Deterioration ◽  
Artificial Neural Network Ann

Modern condition monitoring-based methods are used to reduce maintenance costs, increase aircraft safety, and reduce fuel consumption. In the literature, parameters such as engine fan speeds, vibration, oil pressure, oil temperature, exhaust gas temperature (EGT), and fuel flow are used to determine performance deterioration in gas turbine engines. In this study, a new model was developed to get information about the gas turbine engine’s condition. For this model, multiple regression analysis was carried out to determine the effect of the flight parameters on the EGT parameter and the artificial neural network (ANN) method was used in the identification of EGT parameter. At the end of the study, a network that predicts the EGT parameter with the smallest margin of error has been developed. An interface for instant monitoring of the status of the aircraft engine has been designed in MATLAB Simulink. Any performance degradation that may occur in the aircraft’s gas turbine engine can be easily detected graphically or by the engine performance deterioration value. Also, it has been indicated that it could be a new indicator that informs the pilots in the event of a fault in the sensor of the EGT parameter that they monitor while flying.

Influence of pressure pulsation on the performance of compression system and turbocharged engine

2021 ◽  
pp. 095440702110304
Author(s):  
Zeng Hanxuan ◽  
Wang Baotong ◽  
Zou Wangzhi ◽  
Zheng Xinqian
Keyword(s):  
Pressure Pulsation ◽  
Combustion Engine ◽  
Characteristic Curve ◽  
Pressure Ratio ◽  
Engine Performance ◽  
Concave Function ◽  
Transient Pressure ◽  
Compression System ◽  
Compressor Inlet ◽  
The Impact

Pressure pulsation widely exists in power machinery combining compression components and pipelines. It has substantial effects on the performance of compressor as part of the compression system, as well as the engine. In this paper, the pressure pulsations under different excitation frequencies are measured and analyzed in the intake system of a turbo-charged and inter-cooled internal combustion engine. It is pointed out that the amplification of the pressure pulsation at the compressor inlet and outlet is caused by the coupling effects within the compression system, which consequently lead to the formation of a stable standing wave. Further research indicates that the pulsation at the compressor boundary will cause its pressure ratio to fluctuate. Additionally, because the compressor characteristic curve resembles a concave function, the fluctuation of transient pressure ratio will further cause the time-averaged pressure ratio to decline. Finally, the impact on engine performance is evaluated based on a well-validated simulation model.

scholarly journals Ideal Power Output — An Alternative Aircraft Engine Performance Comparator

1997 ◽  
Author(s):  
Marvin F. Schmidt ◽  
Christopher M. Norden ◽  
Jeffrey M. Stricker
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
State Of The Art ◽  
Pressure Ratio ◽  
Engine Performance ◽  
Aircraft Engine ◽  
The State ◽  
Power Cycle ◽  
Shaft Power ◽  
Bypass Ratio

The gas turbine is applied in four basic configurations; the turbojet, the turbofan, the turboprop and the turboshaft. Comparisons of the performance of these various configurations is difficult since they convert the energy to different forms, i.e. thrust or shaft power. Cycle variables which do not necessarily constitute advancements in the state-of-the-art such as bypass ratio and fan pressure ratio can have a profound effect on thrust and shaft power. Differences in flight speed and altitude capability further confound the comparisons. What is required is a comparison methodology that removes all of these variables and yet puts all the various types of engines on an equitable basis. This paper will provide such a comparison tool. All turbomachinery, regardless of configuration, can be compared with this method.

scholarly journals Turbine Map Extension - Theoretical Considerations and Practical Advice

2020 ◽  
Vol 4 ◽  
pp. 176-189
Author(s):  
Kurzke Joachim
Keyword(s):  
Mass Flow ◽  
Pressure Ratio ◽  
Engine Performance ◽  
Flow Region ◽  
Aircraft Engine ◽  
Special Role ◽  
Power Simulation ◽  
Business Jet ◽  
Flow Limit ◽  
Geometrical Data

Physically sound compressor and turbine maps are the key to accurate aircraft engine performance simulations. Usually, maps only cover the speed range between idle and full power. Simulation of starting, windmilling and re-light requires maps with sub-idle speeds as well as pressure ratios less than unity. Engineers outside industry, universities and research facilities may not have access to the measured rig data or the geometrical data needed for CFD calculations. Whilst research has been made into low speed behavior of turbines, little has been published and no advice is available on how to extrapolate maps. Incompressible theory helps with the extrapolation down to zero flow as in this region the Mach numbers are low. The zero-mass flow limit plays a special role; its shape follows from turbine velocity triangle analysis. Another helpful correlation is how mass flow at a pressure ratio of unity changes with speed. The consideration of velocity triangles together with the enthalpy-entropy diagram leads to the conclusion that in these circumstances flow increases linearly with speed. In the incompressible flow region, a linear relationship exists between torque/flow and flow. The slope is independent of speed and can be found from the speed lines for which data are available. This knowledge helps in extending turbine maps into the regions where pressure ratio is less than unity. The application of the map extension method is demonstrated with an example of a three-stage low pressure turbine designed for a business jet engine.

scholarly journals Comparative study of alternative biofuels on aircraft engine performance

2016 ◽  
Vol 231 (8) ◽  
pp. 1509-1521 ◽  
Author(s):  
Muhammad Hanafi Azami ◽  
Mark Savill
Keyword(s):  
Fuel Consumption ◽  
Engine Performance ◽  
Aircraft Engine ◽  
Specific Fuel Consumption ◽  
Energy Crisis ◽  
Mixing Ratio ◽  
Heating Value ◽  
Fuel Flow ◽  
Lower Heating Value ◽  
Lower Heating

Aviation industries are vulnerable to the energy crisis and simultaneously posed environmental concerns. Proposed engine technology advancements could reduce the environmental impact and energy consumption. Substituting the source of jet fuel from fossil-based fuel to biomass-based fuel will help reduce emissions and minimize the energy crisis. The present paper addresses the analysis of aircraft engine performance in terms of thrust, fuel flow and specific fuel consumption at different mixing ratio percentages (20%, 40%, 50%, 60% and 80%) of alternative biofuel blends already used in flight test (Algae biofuel, Camelina biofuel and Jatropha biofuel) at different flight conditions. In-house computer software codes, PYTHIA and TURBOMATCH, were used for the analysis and modeling of a three-shaft high-bypass-ratio engine which is similar to RB211-524. The engine model was verified and validated with open literature found in the test program of bio-synthetic paraffinic kerosene in commercial aircraft. The results indicated that lower heating value had a significant influence on thrust, fuel flow and specific fuel consumption at every flight condition and at all mixing ratio percentages. Wide lower heating value differences between two fuels give a large variation on the engine performances. Blended Kerosene–Jatropha biofuel and Kerosene–Camelina biofuel showed an improvement on gross thrust, net thrust, reduction of fuel flow and specific fuel consumption at every mixing ratio percentage and at different flight conditions. Moreover, the pure alternative of Jatropha biofuel and Camelina biofuel gave much better engine performances. This was not the case for the Kerosene–Algae blended biofuel. This study is a crucial step in understanding the influence of different blended alternative biofuels on the performance of aircraft engines.

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