scholarly journals Improving the efficiency of aviation turbofan engines by using an intercooler and a recuperative heat exchanger

2020 ◽  
Vol 19 (3) ◽  
pp. 85-99
Author(s):  
H. Omar ◽  
V. S. Kuz'michev ◽  
A. Yu. Tkachenko
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Fuel Efficiency ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Working Process ◽  
Thermodynamic Cycles ◽  
Turbofan Engines ◽  
Aircraft System ◽  
Recuperative Heat Exchanger

Continuous improvement of fuel efficiency of aircraft engines is the main global trend in modern engine construction. To date, aviation gas turbine engines have reached a high degree of thermodynamic and design-and technology perfection. One of the promising ways to further improve their fuel efficiency is the use of complex thermodynamic cycles with turbine exhaust heat regeneration and with intermediate cooling in the process of air compression. Until recently, the use of cycles with a recuperative heat exchanger and an intercooler in aircraft gas turbine engines was restrained by a significant increase in the mass of the power plant due to the installation of heat exchangers. Currently, it has become technologically possible to create compact, light, high-efficiency heat exchangers for use on aircraft without compromising their performance. An important target in the design of engines with heat recovery is to select the parameters of the working process that provide maximum efficiency of the aircraft system. The article focuses on the statement of the task of optimization and choice of rational parameters of the working process of a bypass three-shaft turbojet engine with an intercooler and a recuperative heat exchanger. On the basis of the developed method multi-criteria optimization was carried out by means of numerical simulations. The results of optimization of thermodynamic cycle parameters of a bypass three-shaft turbojet engine with an intercooler and a recuperative heat exchanger in the aircraft system according to such criteria as the total weight of the engine and fuel required for the flight, and the aircraft specific fuel consumption per ton - kilometer of the payload are presented. A passenger aircraft of the Airbus A310-300 type was selected. The developed mathematical model for calculating the mass of a compact heat exchanger, designed to solve optimization problems at the stage of conceptual design of the engine is presented. The developed methods and models are implemented in the ASTRA program. The possibility of improving the efficiency of turbofan engines due to the use of complex thermodynamic cycles is shown.

scholarly journals The effect of heat recovery on the optimal values of helicopter turboshaft engine parameters

2020 ◽  
Vol 19 (4) ◽  
pp. 43-57
Author(s):  
H. H. Omar ◽  
V. S. Kuz'michev ◽  
A. O. Zagrebelnyi ◽  
V. A. Grigoriev
Keyword(s):  
Heat Exchanger ◽  
Gas Turbine ◽  
Heat Recovery ◽  
Thermodynamic Cycle ◽  
Gas Turbine Engine ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Working Process ◽  
Turbine Engine ◽  
Recuperative Heat Exchanger

Recent studies related to fuel economy in air transport conducted in our country and abroad show that the use of recuperative heat exchangers in aviation gas turbine engines can significantly, by up to 20...30%, reduce fuel consumption. Until recently, the use of cycles with heat recovery in aircraft gas turbine engines was restrained by a significant increase in the mass of the power plant due to the installation of a heat exchanger. Currently, there is a technological opportunity to create compact, light, high-efficiency heat exchangers for use on aircraft without compromising their performance. An important target in the design of engines with heat recovery is to select the parameters of the working process that provide maximum efficiency of the aircraft system. The article focused on setting of the optimization problem and the choice of rational parameters of the thermodynamic cycle parameters of a gas turbine engine with a recuperative heat exchanger. On the basis of the developed method of multi-criteria optimization the optimization of thermodynamic cycle parameters of a helicopter gas turbine engine with a ANSAT recuperative heat exchanger was carried out by means of numerical simulations according to such criteria as the total weight of the engine and fuel required for the flight, the specific fuel consumption of the aircraft for a ton- kilometer of the payload. The results of the optimization are presented in the article. The calculation of engine efficiency indicators was carried out on the basis of modeling the flight cycle of the helicopter, taking into account its aerodynamic characteristics. The developed mathematical model for calculating the mass of a compact heat exchanger, designed to solve optimization problems at the stage of conceptual design of the engine and simulation of the transport helicopter flight cycle is presented. The developed methods and models are implemented in the ASTRA program. It is shown that optimal parameters of the working process of a gas turbine engine with a free turbine and a recuperative heat exchanger depend significantly on the heat exchanger effectiveness. The possibility of increasing the efficiency of the engine due to heat regeneration is also shown.

Development of Ceramic Heat Exchangers for Indirect Fired Gas Turbines

1982 ◽  
Author(s):  
W. T. Bakker ◽  
D. Kotchick
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Gas Turbines ◽  
Large Scale ◽  
Working Fluid ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Short Term ◽  
The Status

Utilizing dirty fuels such as coal in gas turbine engines requires that heat input to the cycle working fluid occur through a heat exchanger. For high cycle efficiencies such a heat exchanger must operate in the 700–1400 KPA, 1100–1200°C (100–200 psi, 2000–2200°F) range. In this temperature range, ceramic heat exchangers are required. Ceramic heat exchangers that can operate in this regime have been under development for several years on a very modest scale. These programs are briefly reviewed. Major material issues are reviewed and the status of each is presented. Mechanical reliability and joining technology have been successfully demonstrated in short term tests. Long-term durability and the manufacturing technology to produce large scale components reproducibly remains to be demonstrated in the future.

Improvements in Part-Load Efficiency by Reducing Pressure Ratio in Regenerative Gas-Turbine Engines

1985 ◽  
Author(s):  
Theodosios P. Korakianitis ◽  
David Gordon Wilson
Keyword(s):  
Heat Exchanger ◽  
Gas Turbine ◽  
Heat Exchangers ◽  
Pressure Ratio ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Design Point ◽  
Part Load ◽  
Compressor Pressure Ratio ◽  
Point Pressure

To obtain equal thermal efficiencies in gas-turbine engines, designers have the freedom (if space and mass constraints are not limiting) of exchanging compressor pressure ratio for heat-exchanger effectiveness. Because heat exchangers can have lower losses than compressors, a high-effectiveness heat-exchanger cycle can have a much higher thermal efficiency (theoretically 55–60%) than is possible with unregenerated cycles. What has not been known up to now is the effect of design-point pressure ratio on the part-load efficiency of gas-turbine engines. The work reported here shows that, for similar turbomachinery technology, design-point and part-load efficiencies improve as the design-point pressure ratio decreases and the heat-exchanger thermal ratio increases.

Paper 11: Regenerators for High Temperature Gas Turbine Engines

1968 ◽  
Vol 183 (14) ◽  
pp. 110-120
Author(s):  
R. N. Penny
Keyword(s):  
Heat Exchanger ◽  
Gas Turbine ◽  
Glass Ceramic ◽  
Gas Turbines ◽  
First Generation ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Regenerative Heat ◽  
Complete Failure ◽  
Recuperative Heat Exchanger

In various companies throughout the world a first generation of production vehicle gas turbine engines are being engineered. A vital component involved is the regenerative heat exchanger. The relative merits of the rotary regenerative and static recuperative heat exchanger are compared. Thermal efficiency and competitive initial cost are the two vital issues involved in the design of small gas turbines for the commercial establishment of gas turbine vehicles. The selection of a material for the rotary regenerator is essentially related to resolving the two vital issues of future small gas turbines and is, therefore, analysed. The account of the pioneering work involved in engineering the glass ceramic and other non-metal rotary regenerators includes a complete failure analysis based on running experience with over 200 ceramic regenerators. The problems of sealing, supporting and manufacturing the glass ceramic rotary generator are discussed and future practical regenerative designs are outlined. Heat exchange theory applied to small gas turbines is also reviewed.

Future Research Directions for Ship Propulsion Materials

2009 ◽  
Author(s):  
David A. Shifler
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Fuel Efficiency ◽  
High Strength ◽  
Turbine Engines ◽  
Future Research ◽  
Oxide Surface ◽  
Materials Testing ◽  
Gas Turbine Engines ◽  
Protective Oxide

High temperature applications demand materials that have a variety of properties such as high strength, toughness, creep resistance, fatigue resistance, as well as resistance to degradation by their interaction with the environment. All potential metallic materials are unstable in many high temperatures environments without the presence of a protective coating on the component surface. High temperature alloys derive their resistance to degradation by forming and maintaining a continuous protective oxide surface layer that is slow-growing, very stable, and adherent. In aggressive environments, the superalloy oxidation and corrosion resistance needs to be augmented by coatings. Propulsion materials for Naval shipboard gas turbine engines are subjected to the corrosive environment of the sea to differing degrees. Increasing fuel efficiency and platform capabilities require higher operating temperatures that may lead to new degradation modes of coatings and materials. Fuel contaminants or the lack of contaminants from alternative synthetic fuels may also strongly influence coating and/or materials performance which, in turn, can adversely affect the life in these propulsion or auxiliary gas turbine engines. This paper will dwell on some past results of materials testing and offer some views on future directions into materials research in high temperature materials in aggressive environments that will lead to new advanced propulsion materials for shipboard applications.

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.

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

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%.

Exergetic Analysis of a Cross-Flow Microchannel Heat Exchanger for Bleed Air Cooling in Aircraft Gas Turbine Engines

2014 ◽  
Author(s):  
Matthew B. Rivera ◽  
Randall D. Manteufel
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Heat Exchanger ◽  
Pressure Ratio ◽  
Cross Flow ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Exergy Destruction ◽  
High Pressure Ratio ◽  
Exergetic Analysis

A current issue with high-pressure-ratio compressors found in aircraft engines is the temperature of the air exiting the compressor. The exiting air is used as coolant for engine components found in later stages of the engine such as first-stage turbine blades, and afterburner walls. A viable option for reducing outlet temperature of high-pressure-ratio compressors is to “bleed-off” a fraction of the air which is cooled in a heat exchanger by rejecting heat into the liquid fuel stream and then use the air for cooling critical components downstream. Bleeding off air from the outlet of the compressor has two benefits: (1) air temperature is reduced, and (2) fuel temperature is elevated. Along with reduced air temperatures, the fuel will ultimately receive the heat lost from the air, making the fuel more ideal for combustion purposes. The higher temperature the fuel is received in the combustion process, the greater the work output will be according to the basics of thermodynamic combustion. The objective of this case study is to optimize the efficiency of the cross-flow micro channel heat exchanger, with respect to (1) volume (1.75–2.75 mm3) and heat transfer, and (2) weight (0.15–.25 N) and heat transfer. The optimization of the heat exchanger will be evaluated within the bounds of the 2nd law of thermodynamics (exergy). The only effective way to measure the 2nd law of thermodynamics is through exergy destruction or its equivalent form: entropy generation as a factor of dead state temperature. With relations and equations obtained to design an optimal heat exchanger, applications to high performance aircraft gas turbine engines is considered through exergy. The importance of developing an exergetic analysis for a thermal system is highly effective for identifying area’s within the system that have the path of highest resistance to work potential through various modes of heat transfer and pressure loss. Thus, optimization to reduce exergy destruction is sought after through this design method alongside verifying other heat exchanger methods through effectiveness.

scholarly journals Performance Assessment of the Thermodynamic Cycle in a Multi-Mode Gas Turbine Engine

2021 ◽  
Author(s):  
Viktors Gutakovskis ◽  
Vladimirs Gudakovskis
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Gas Turbine Engine ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Working Process ◽  
Adaptive Approach ◽  
Turbine Engine ◽  
Operation Modes ◽  
Multi Mode

This chapter discusses the direction of development of promising multimode aviation gas turbine engines (GTE). It is shown that the development of GTE is on the way to increase the parameters engine workflow: gas temperatures in front of the turbine (T*G) and the degree of pressure increase in the compressor (P*C). It is predicted that the next generation engines will operate with high parameters of the working process, T*G = 2000–2200 K, π*C = 60–80. At this temperature of gases in front of the turbine, the working mixture in the combustion chamber (CC) is stoichiometric, which sharply narrows the range of stable operation of the CC and its efficiency drops sharply in off-design gas turbine engine operation modes. To expand the range of effective and stable work, it is proposed to use an advanced aviation GTE: Adaptive Type Combustion Chamber (ATCC). A scheme of the ATCC and the principles of its regulation in the system of a multi-mode gas turbine engine are presented. The concept of an adaptive approach is given in this article. There are two main directions for improving the characteristics of a promising aviation gas turbine engine. One is a complication of the concepts of aircraft engines and the other one is an increase in the parameters of the working process, the temperature of the gases in front of the turbine (T*G) and the degree of increasing pressure behind the compressor (π*C). It is shown how the principles of adaptation are used in these areas. The application of the adaptation principle in resolving the contradiction of the possibility of obtaining optimal characteristics of a high-temperature combustion chamber (CC) of a gas turbine engine under design (optimal) operating conditions and the impossibility of their implementation when these conditions change in the range of acceptable (non-design) gas turbine operation modes is considered in detail. The use of an adaptive approach in the development of promising gas turbine engines will significantly improve their characteristics and take into account unknown challenges.

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