Investigation of Fixed-Rake Sampling System for the Assessment of Emission Characteristics of Gas Turbine Engines

1983 ◽  
Author(s):  
H. C. Low ◽  
A. P. Dowling
Keyword(s):  
Environmental Protection Agency ◽  
Sampling Methods ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Aircraft Engines ◽  
Sampling System ◽  
Turbofan Engine ◽  
Optimum Configuration ◽  
Compliance Testing ◽  
The Us

The regulations proposed by the US Environmental Protection Agency to limit the quantity of pollutant gases emitted by aircraft engines allow the exhaust of engines submitted for compliance testing to be sampled by a fixed-multipoint rake. However, the onus is placed on the manufacturer to prove the representativeness of the samples taken in this relatively cheap fashion. To illustrate best possible accuracies, the exhaust of an M45H civil turbofan engine has hen extensively sampled and a computer program has been used to select the optimum configuration of a cruciform rake. The program demanded excellent agreement between the sampling methods and this proved to be the case in actual tests. However, the program also indicates that the errors of a simply designed rake giving area-weighted samples would also be less than 10%. Sampling in the FAA diamond pattern would give rise to a 20% error in CO emissions.

Determination of Cycle Configuration of Gas Turbines and Aircraft Engines by Optimization Procedure

1990 ◽  
Author(s):  
Yoshiharu Tsujikawa ◽  
Makoto Nagaoka
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Specific Impulse ◽  
Optimization Procedure ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Aircraft Engines ◽  
Scramjet Engine ◽  
Aero Engines

This paper is devoted to the analyses and optimization of simple and sophisticated cycles, particularly for various gas turbine engines and aero-engines (including scramjet engine) to achive the maximum performance. The optimization of such criteria as thermal efficiency, specific output and total performance for gas turbine engines, and overall efficiency, non-dimensional thrust and specific impulse for aero-engines have been performed by the optimization procedure with multiplier method. The comparisons of results with analytical solutions establishes the validity of the optimization procedure.

scholarly journals Some Aerodynamic Problems of Aircraft Engines: Fifty Years After -The 2007 IGTI Scholar Lecture-

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Edward M. Greitzer
Keyword(s):  
Gas Turbine ◽  
Collaborative Research ◽  
Research Process ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Aircraft Engines ◽  
Jet Engines ◽  
Organizational Boundaries ◽  
Turbine Performance ◽  
Single Discipline

Problems of high technological interest, for example the development of gas turbine engines, span disciplinary, and often organizational, boundaries. Although collaboration is critical in advancing the technology, it has been less a factor in gas turbine research. In this paper it is proposed that step changes in gas turbine performance can emerge from collaborative research endeavors that involve the development of integrated teams with the needed range of skills. Such teams are an important aspect in product development, but they are less familiar and less subscribed to in the research community. The case histories of two projects are given to illustrate the point: the development of the concept of “smart jet engines” and the Silent Aircraft Initiative. In addition to providing a capability to attack multidisciplinary problems, the way in which collaboration can enhance the research process within a single discipline is also discussed.

scholarly journals Mathematical model of turbofan engine weight estimation taking into account the engine configuration and size

2021 ◽  
Vol 20 (1) ◽  
pp. 5-13
Author(s):  
S. V. Avdeev
Keyword(s):  
Gas Turbine ◽  
Conceptual Design ◽  
Air Flow ◽  
Turbine Engines ◽  
Average Error ◽  
Gas Turbine Engines ◽  
Turbofan Engine ◽  
Turbofan Engines ◽  
Structural Layout ◽  
Mixing Chamber

The paper presents a new correlation-regression model of estimating the turbofan engine weight considering the effect of the engines design schemes and dimensions. The purpose of this study was to improve the efficiency of the conceptual design process for aircraft gas turbine engines. Information on 183 modern turbofan engines was gathered using the available sources: publications, official websites, reference books etc. The statistic information included the values of the total engine air flow, the total turbine inlet gas temperature, the overall pressure ratio and the bypass ratio, as well as information on the structural layout of each engine. The engines and the related statistics were classified according to their structural layout and size. Size classification was based on the value of the compressor outlet air flow through the gas generator given by the parameters behind the compressor. Depending on the value of this criterion, the engines were divided into three groups: small-sized, medium-sized gas turbine engines, and large gas turbine engines. In terms of the structural layout, all engines were divided into three groups: turbofan engines without a mixing chamber, engines with a mixing chamber and afterburning turbofan engines. Statistical factors of the improved weight model were found for the respective groups of engines, considering their design and size. The coefficients of the developed model were determined by minimizing the standard deviations. Regression analysis was carried out to assess the quality of the developed model. The relative average error of approximation of the developed model was 8%, the correlation coefficient was 0,99, and the standard deviation was 10,2%. The model was found to be relevant and reliable according to Fisher's test. The obtained model can be used to assess the engine weight at the stage of conceptual design and for its optimization as part of an aircraft.

The Reduction of Gas Turbine Idle Emissions by Fuel Zoning for Compressor Bleed

1974 ◽  
Vol 96 (3) ◽  
pp. 807-810
Author(s):  
T. R. Clements
Keyword(s):  
Gas Turbine ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Turbofan Engine ◽  
Total Hydrocarbon ◽  
Annular Combustor ◽  
Full Power

Two methods of reducing the idle emissions of gas turbine engines have been investigated. The methods were (1) fuel zoning, whereby a portion of the fuel nozzles were shut down and all of the fuel passed through the remaining nozzles and (2) larger than normal compressor overboard bleed. Both methods operate on the fact that a combustor’s efficiency increases as the fuel/air ratio is increased from idle to full power conditions. Fuel zoning increases the local fuel/air ratio making those portions of the combustor which are operating more efficient. This method has been shown to reduce the idle emission of total hydrocarbon by 5 to 1 in a double annular combustor sized for a large augmented turbofan engine. Operating with a larger than normal compressor overboard bleed allows increasing fuel/air ratio without increasing idle thrust. By using this method in a P&WA™ JT3C-7 engine a reduction of 2 to 1 in the emission of total hydrocarbon was demonstrated.

Some Aerodynamic Problems of Aircraft Engines: Fifty Years After

2007 ◽  
Author(s):  
Edward M. Greitzer
Keyword(s):  
Gas Turbine ◽  
Research Process ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Aircraft Engines ◽  
Jet Engines ◽  
Case Histories ◽  
Disciplinary Boundaries ◽  
Turbine Performance ◽  
Single Discipline

Problems of high technological interest, for example the development of gas turbine engines, span disciplinary boundaries. Collaboration is critical in advancing the technology, but it has been less a factor in gas turbine research. In this paper it is proposed that step changes in gas turbine performance can emerge from such collaborative endeavors. In these, success depends on the development of integrated teams with the appropriate range of skills. This is well known in product development, but it is less familiar, and less subscribed to, in the research community. Case histories of two projects are given to illustrate the point: the development of the concept of “smart jet engines” and the Silent Aircraft Initiative. In addition to providing the ability to attack multidisciplinary issues discussion is also given about the way in which collaboration can enhance the research process within a single discipline.

scholarly journals Methods of clustering parameters in the creation of neural network multi-mode dynamic models of aircraft engines

2021 ◽  
pp. 71-78
Author(s):  
Александр Анатолиевич Тамаргазин ◽  
Людмила Борисовна Приймак ◽  
Валерий Владиславович Шостак
Keyword(s):  
Neural Network ◽  
Cluster Analysis ◽  
Gas Turbine ◽  
Technical Condition ◽  
Technical State ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Aircraft Engines ◽  
Clustering Methods ◽  
Aviation Engines

The presence on modern aviation gas-turbine engines of dozens and even hundreds of sensors for continuous registration of various parameters of their operation makes it possible to collect and process large amounts of information. This stimulates the development of monitoring and diagnostic systems. At the same time the presence of great volumes of information is not always a sufficient condition for making adequate managerial decisions, especially in the case of evaluation of the technical condition of aviation engines. Thus it is necessary to consider, that aviation engines it is objects which concern to individualized, i.e. to such which are in the sort unique. Therefore, the theory of creating systems to assess the technical state of aircraft engines is formed on the background of the development of modern neural network technology and requires the formation of specific methodological apparatus. From these positions in the article the methods which are used at carrying out clustering of the initial information received at work of modern systems of an estimation and forecasting of a technical condition of aviation gas-turbine engines are considered. This task is particularly relevant for creating neural network multimode models of aircraft engines used in technical state estimation systems for identification of possible failures and damages. Metric, optimization and recurrent methods of input data clustering are considered in the article. The main attention is given to comparison of clustering methods in order to choose the most effective of them for the aircraft engine condition evaluation systems and suitable for implementation of systems with meta-learning. The implementation of clustering methods of initial data allows us to breakdown diagnostic images of objects not by one parameter, but by a whole set of features. In addition, cluster analysis, unlike most mathematical-statistical methods do not impose any restrictions on the type of objects under consideration, and allows us to consider a set of raw data of almost arbitrary nature, which is very important when assessing the technical condition of aircraft engines. At the same time cluster analysis allows one to consider a sufficiently large volume of information and sharply reduce, compress large arrays of parametrical information, make them compact and visual.

PULSE THERMAL CONTROL OF MOISTURE IN AIRCRAFT LIQUID FUELS

2020 ◽  
Author(s):  
A. A. Starostin ◽  
◽  
D. V. Volosnikov ◽  
P. V. Skripov ◽  
◽  
...  
Keyword(s):  
Gas Turbine ◽  
Thermal Control ◽  
Liquid Fuels ◽  
Turbine Engines ◽  
Jet Fuels ◽  
Gas Turbine Engines ◽  
Aircraft Engines ◽  
Turbine Engine ◽  
Fuel Tanks

The reliability of the operation of aircraft engines is determined by chemical reliability, which is due to the quality of the used fuels and lubricants: jet fuels and aircraft oils and their influence on the operational properties of units and assemblies of gas turbine engines. One of the factors reducing the smooth operation of a gas turbine engine is the presence of water traces in the fuel. The main reason is the condensation of water traces in the fuel tanks and its freezing in filters and fuel pipes at temperature differences. In addition, water dissolved in fuel significantly increases the wear of fuel system components and friction pairs.

Exhaust Emission Characteristics of Aircraft Gas Turbine Engines

1972 ◽  
Author(s):  
A. W. Nelson
Keyword(s):  
Gas Turbine ◽  
Environmental Protection Agency ◽  
Turbine Engines ◽  
Exhaust Emission ◽  
Emission Characteristics ◽  
Gas Turbine Engines ◽  
Protection Agency ◽  
Variation Characteristics ◽  
Exhaust Stream ◽  
Documentation Program

Accurate measurement of the exhaust emissions of aircraft gas turbine engines presents a challenge not only because of the high velocities and temperatures of the exhaust stream, but also because of the variation of the exhaust constitutents over the relatively large-cross-section of the jet stream itself. Other factors which affect exhaust emission level include ambient temperature and humidity. This paper presents the results of independent efforts by Pratt & Whitney Aircraft to identify emission variation characteristics together with results of an exhaust emission documentation program funded by the Environmental Protection Agency. Methods and techniques employed in the above programs are also discussed. The results of these programs indicate that additional effort is required to properly evaluate and understand the emission characteristics of aircraft gas turbine engines.

Design Parameters for an Aircraft Engine Exit Plane Particle Sampling System

2010 ◽  
Vol 133 (2) ◽  
Author(s):  
Hsi-Wu Wong ◽  
Zhenhong Yu ◽  
Michael T. Timko ◽  
Scott C. Herndon ◽  
Elena de la Rosa Blanco ◽  
...  
Keyword(s):  
Experimental Data ◽  
System Design ◽  
Gas Turbine ◽  
Black Carbon ◽  
Particle Formation ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Exit Plane ◽  
Sampling System ◽  
Sampling Line

The experimental data and numerical modeling were utilized to investigate the effects of exhaust sampling parameters on the measurements of particulate matter (PM) emitted at the exit plane of gas-turbine engines. The results provide guidance for sampling system design and operation. Engine power level is the most critical factor that influences the size and quantity of black carbon soot particles emitted from gas-turbine engines and must be considered in sampling system design. The results of this investigation indicate that the available soot surface area significantly affects the amount of volatile gases that can condense onto soot particles. During exhaust particle measurements, a dilution gas is typically added to the sampled exhaust stream to suppress volatile particle formation in the sampling line. Modeling results indicate that the dilution gas should be introduced upstream before a critical location in the sampling line that corresponds to the onset of particle formation microphysics. Also, the dilution gas should be dry for maximum nucleation suppression. In most aircraft PM emissions measurements, the probe-rake systems are water cooled and the sampling line may be heated. Modeling results suggest that the water cooling of the probe tip should be limited to avoid overcooling the sampling line wall temperature and, thus, minimize additional particle formation in the sampling line. The experimental data show that heating the sampling lines will decrease black carbon and sulfate PM mass and increase organic PM mass reaching the instruments. Sampling line transmission losses may prevent some of the particles emitted at the engine exit plane from reaching the instruments, especially particles that are smaller in size. Modeling results suggest that homogeneous nucleation can occur in the engine exit plane sampling line. If newly nucleated particles, typically smaller than 10 nm, are indeed formed in the sampling line, sampling line particle losses provide a possible explanation, in addition to the application of dry diluent, that they are generally not observed in the PM emissions measurements.

scholarly journals Thermodynamic designing of the small-scale gas turbine engine family with common core

2018 ◽  
Vol 220 ◽  
pp. 03007
Author(s):  
Andrey Tkachenko ◽  
Evgeny Filinovaroslav Ostapyuk ◽  
Viktor Rybakov ◽  
Daria Kolmakova
Keyword(s):  
Gas Turbine ◽  
Common Core ◽  
Turbine Engines ◽  
Small Scale ◽  
Gas Turbine Engines ◽  
Working Process ◽  
Turbofan Engine ◽  
Engine Family ◽  
Power Turbine ◽  
The Cost

The paper describes the method of selecting the working process parameters of a family of small-scale gas turbine engines (GTE) with common core. As an example, the thermodynamic design of a family of small-scale gas turbine engines (SGTE) with common core was carried out. The engine family includes a small-scale turbojet engine (STJE) and a gas turbine plant (GTP), which electric generator is driven by power turbine. The selection of rational values for the working process parameters of STJE and GTP was carried out in CAE system ASTRA on the basis of nonlinear optimization of these parameters, taking into account functional and parametric constraints. The quantitative results of deterioration in the performance of the engines of the family with common core are obtained in comparison with the engines with the optimum core for each type. However, the advanced creation of a common core can reduce the cost and timing of the engine creation, ensure its higher reliability (due to the development of the base common core) and reduce the cost of its production. The method of selecting the parameters of the working process of the GTE family with common core presents the solution to more complex problems, such as the possibility of developing a family consisting of five engines: a turbojet engine, turbofan engine, turbofan engine with a complex cycle, GTE with power turbine (GTE-PT), GTE-PT with recovery.

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