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

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.

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Introduction to the problem of calculating the parameters of the mixing chamber of an afterburning bypass engine

VESTNIK of the Samara State Aerospace University ◽

10.18287/2541-7533-2021-20-3-57-64 ◽

2021 ◽

Vol 20 (3) ◽

pp. 57-64

Author(s):

O. D. Karev

Keyword(s):

Mathematical Modeling ◽

Chemical Composition ◽

Mathematical Models ◽

Gas Turbine ◽

Turbine Engines ◽

Gas Turbine Engines ◽

Turbine Engine ◽

The Core ◽

Mixing Chamber ◽

Mixing Chambers

The article considers the problem of calculation accuracy when using mathematical models of gas-turbine engines of the second level of complexity, using the example of a device for mixing the flows of the core engine and the bypass duct of a gas turbine engine, and suggests methods for solving it. The processes taking place in mixing chambers of air-breather engines are considered to be difficult for mathematical modeling since the exchange of kinetic and thermal energies of the flows characterized by different velocities, pressures, temperatures and chemical composition occurs in them simultaneously. The mixer does not only ensure mixing of flows from different engine ducts, but also acts as a kind of throttle. It regulates the pressure downstream of the fan and, consequently, air consumption in the bypass duct, thus affecting directly the fan characteristics and the distribution of flows over the engine ducts. The paper presents the dependencies of the workflow parameters that allow for more accurate verification of mixer models of the second level of complexity.

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Correlation-regression models for calculating the weight of small-scale aircraft gas turbine engines

MATEC Web of Conferences ◽

10.1051/matecconf/201822003004 ◽

2018 ◽

Vol 220 ◽

pp. 03004

Author(s):

Evgeny Filinov ◽

Daria Kolmakova ◽

Sergey Avdeev ◽

Sergey Krasilnikov

Keyword(s):

Gas Turbine ◽

Regression Models ◽

Design Stage ◽

Turbine Engines ◽

Small Scale ◽

Gas Turbine Engines ◽

Turbofan Engines ◽

New Correlation ◽

Engine Design ◽

Weight Calculation

Several new correlation-regression models of weight calculation for small-scale aircraft gas turbine engines are proposed for their conceptual design stage. A comparison of the obtained weight models with each other and with the Kuz’michev model is carried out. Based on the obtained results, conclusions about the feasibility and scope of their application are drawn. New correlation-regression models differ from each other in the number of input parameters, as well as in the accuracy of forecasting the weight. In the course of the work, a database of main data and thermodynamic parameters of turbofan engines (TFE) is created consisting of 92 small-scale TFEs with thrust less than 50 kN. Based on the collected statistics, formulas were obtained that allow calculating the weight at the initial stage of engine design. The error in calculating the weight by these models is in range from 10% to 30%.

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

Journal of Engineering for Industry ◽

10.1115/1.3438445 ◽

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.

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

MATEC Web of Conferences ◽

10.1051/matecconf/201822003007 ◽

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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Thermodynamic Multi-Criteria Optimization of the Unified Engine Core for the Line of Turbofan Engines

Volume 1: Aircraft Engine; Fans and Blowers; Marine ◽

10.1115/gt2016-57854 ◽

2016 ◽

Cited By ~ 1

Author(s):

Viktor N. Rybakov ◽

Venedikt S. Kuz'michev ◽

Andrey Y. Tkachenko ◽

Ilia N. Krupenich

Keyword(s):

Gas Turbine ◽

Turbine Engines ◽

Gas Turbine Engines ◽

Multi Objective ◽

Turbofan Engines ◽

Selection Of

Although development of the line of gas turbine engines on the basis of a unified engine core is a widely used practice, the method of selection of the most efficient values of engine core parameters has virtually never been published. The paper describes the method of optimization of values of engine core parameters jointly with optimization of values of every engine forming the line of engines developed on the basis of this core. Both stages of optimization are multi-objective and fulfilled using the results of simulation of engine as a subsystem of the airframe.

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Virtual Gas Turbines: Geometry and Conceptual Description

Volume 1: Aircraft Engine; Ceramics; Coal, Biomass and Alternative Fuels; Wind Turbine Technology ◽

10.1115/gt2011-46437 ◽

2011 ◽

Cited By ~ 11

Author(s):

Luca di Mare ◽

Davendu Y. Kulkarni ◽

Feng Wang ◽

Artyom Romanov ◽

Pandia R. Ramar ◽

...

Keyword(s):

Gas Turbine ◽

Physical Modeling ◽

Gas Turbines ◽

Boundary Data ◽

Turbine Engines ◽

Gas Turbine Engines ◽

Turbofan Engine

This paper documents the construction of a Virtual Engine, with particular reference to its geometry and conceptual description.. The phrase Virtual Engine denotes a system which allows simulations of whole gas-turbine engines to be undertaken at any desired level of fidelity or physical modeling. In order to be of any practical use, the system must allow the computations to be setup as automatically as possible and needs to contain provisions for the exchange of boundary data between adjacent computational domains — e.g. solid-gas interfaces. The paper illustrates the application of the system to the representation and analysis of a modern commercial turbofan engine.

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