Aero Engine Concepts Beyond 2030: Part 1 - the Steam Injecting and Recovering Aero Engine

Abstract Recognizing the attention currently devoted to the environmental impact of aviation, this three-part publication series introduces two new aircraft propulsion concepts for the timeframe beyond 2030. This first part focuses on the steam injecting and recovering aero engine concept. In the second part, the free-piston Composite cycle engine concept is presented. A third publication, building upon those two concepts, presents the project which aims for demonstrating the proof of concept with numerical simulation and test-bench experiments up to a technology readiness level of three. In the steam injecting and recovering aero engine concept, exhaust heat generated steam is injected into the combustion chamber. The humidified mass flow contains significantly more extractable energy than air. Furthermore, the pumping of liquid water up to the necessary pressure requires a magnitude less power than the compression of air, which reduces the internal power demand. Both lead to a noticeable increase in specific power compared to a conventional gas turbine and, foremost, to a significant increase in thermodynamic efficiency. By use of a condenser, installed behind the steam generator, the water is recovered from the exhaust gas-steam mixture. The proposed concept is expected to reduce fuel burn and CO2 emissions by about 15 % and NOx formation can be almost completely avoided compared to state-of-the-art engines of the same technology level. Moreover, the described concept has the potential to drastically reduce or even avoid the formation of condensation trails. Thus, the steam injecting and recovering aero engine concept operated with sustainable aviation fuels offers the potential for climate-neutral aviation. Based on consistent thermodynamic descriptions, preliminary designs and initial performance studies, the potentials of the concepts are analyzed. Complementarily, a detailed discussion on concrete engineering solutions considers the implementation into aircraft. Finally, the impact on emissions is outlined.

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An Intercooled Recuperative Aero Engine for Regional Jets

Volume 3A: Coal, Biomass and Alternative Fuels; Cycle Innovations; Electric Power; Industrial and Cogeneration ◽

10.1115/gt2014-26387 ◽

2014 ◽

Cited By ~ 1

Author(s):

Maximilian Kormann ◽

Reinhold Schaber

Keyword(s):

Heat Exchanger ◽

Heat Exchangers ◽

Thermodynamic Efficiency ◽

Parameter Study ◽

Nox Emissions ◽

Turbofan Engines ◽

Fuel Burn ◽

Aero Engine ◽

Aero Engines ◽

Regional Jets

Flying requires a high power density in the propulsion system. Currently only turbofan engines can provide the required power at a low system mass. To counter a potential negative impact of aircraft emissions on global climate, the agreement Flightpath 50, created by European research establishments and industries, has set the target to reduce overall CO2 emissions from the year 2000 to 2050 by 75 %. In contrast, the air traffic volume has been growing constantly since the 1980s and will be growing further. Hence the fuel burn of aero engines has to be reduced to reach the Flightpath 50 target. High-end component technology has nearly exhausted full potential in the improvement of conventional turbofan engines. Further significant progress can only be achieved by new engine concepts. The geared turbofan has proven the feasibility of this approach. The introduction of a gear allows the IPC and LPT to run at more suitable speeds with the consequence of a lower stage count compared to conventional turbofans. According to Pratt&Whitney this will reduce the fuel burn by ”15–16% versus today’s best engines” [1]. As a next step towards Flightpath 50 MTU Aero Engines AG envisioned the Intercooled Recuperative Aero Engine (IRA) for long-haul application. This concept increases the thermodynamic efficiency of the core engine by utilizing two heat exchangers: an intercooler reduces the work which is necessary for the compression. A recuperator transfers heat of the exhaust gas to the compressed gas entering the burner. In long-haul aircraft the increased engine mass due to the heat exchangers has a lower influence on the fuel burn. To broaden the research, this paper investigates the application of the IRA for regional jets. An extensive predesign parameter study was performed to find the optimal IRA configuration for regional jets. Not only has fuel consumption been taken into consideration, additionally the influence of the increased weight of the IRA has been included. In optimum, the fuel burn on a regional mission according to this study could be reduced in the order of 1–2%. However, the overall pressure ratio is much lower compared to modern turbofan engines, which leads to relatively low NOx emissions. It allows the introduction of Lean Premixed Prevaporized (LPP) burner technology, promising an additional significant reduction in NOx emissions compared to modern turbofan engines. Compared to a longhaul application the heat exchangers are not a scaled version but the result of a cycle optimization considering the available space. The paper also gives an outlook for an innovative three dimensional heat exchanger. The novel heat exchanger arrangement promises a better integration into the annulus at turbine exit and less aerodynamical pressure losses due to 3D-effects.

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THE FUTURE OF PASSENGER AIR TRANSPORT – VERY LARGE AIRCRAFT AND OUT KEY HUMAN FACTORS AFFECTING THE OPERATION AND SAFETY OF PASSENGER AIR TRANSPORT

Acta Polytechnica CTU Proceedings ◽

10.14311/app.2017.12.0104 ◽

2017 ◽

Vol 12 ◽

pp. 104

Author(s):

Petra Skolilova

Keyword(s):

Human Factors ◽

Human Error ◽

Operating Cost ◽

Aircraft Design ◽

Air Transport ◽

Final Decision ◽

Factors Affecting ◽

Fuel Burn ◽

The Future ◽

The Impact

The article outlines some human factors affecting the operation and safety of passenger air transport given the massive increase in the use of the VLA. Decrease of the impact of the CO2 world emissions is one of the key goals for the new aircraft design. The main wave is going to reduce the burned fuel. Therefore, the eco-efficiency engines combined with reasonable economic operation of the aircraft are very important from an aviation perspective. The prediction for the year 2030 says that about 90% of people, which will use long-haul flights to fly between big cities. So, the A380 was designed exactly for this time period, with a focus on the right capacity, right operating cost and right fuel burn per seat. There is no aircraft today with better fuel burn combined with eco-efficiency per seat, than the A380. The very large aircrafts (VLAs) are the future of the commercial passenger aviation. Operating cost versus safety or CO2 emissions versus increasing automation inside the new generation aircraft. Almost 80% of the world aircraft accidents are caused by human error based on wrong action, reaction or final decision of pilots, the catastrophic failures of aircraft systems, or air traffic control errors are not so frequent. So, we are at the beginning of a new age in passenger aviation and the role of the human factor is more important than ever.

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Multi-platform app-embedded model for hybrid air-breathing rocket-cycle engine in hypersonic atmospheric ascent

The Aeronautical Journal ◽

10.1017/aer.2021.3 ◽

2021 ◽

pp. 1-23

Author(s):

S.E. Tsentis ◽

V.G. Gkoutzamanis ◽

A.D. Gaitanis ◽

A.I. Kalfas

Keyword(s):

Specific Impulse ◽

Performance Parameters ◽

Interested Reader ◽

Component Level ◽

Air Breathing ◽

Evaluation Of Performance ◽

Embedded Model ◽

The Impact ◽

Rocket Technology ◽

Engine Concept

ABSTRACT This paper presents a performance analysis on a novel engine concept, currently under development, in order to achieve hybrid air-breathing rocket technology. A component-level approach has been developed to simulate the performance of the engine at Mach 5, and the thermodynamic interaction of the different working fluids has been analysed. The bypass ramjet duct has also been included in the model. This facilitates the improved evaluation of performance parameters. The impact of ram drag induced by the intake of the engine has also been demonstrated. The whole model is introduced into a multi-platform application for aeroengine simulation to make it accessible to the interested reader. Results show that the bypass duct modelling increases the overall efficiency by approximately 7%. The model calculates the specific impulse at approximately 1800 seconds, which is 4 times higher than any chemical rocket.

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Topology-Optimized Intermediate Casing of Aero Engine and Comparative Evaluation of Titanium and Composite Architecture in Terms of Load Capacity and Weight Reduction

Volume 5: Structures and Dynamics, Parts A and B ◽

10.1115/gt2008-50644 ◽

2008 ◽

Author(s):

Markus Kober ◽

Olaf Lenk ◽

Thomas Klauke ◽

Arnold Ku¨hhorn

Keyword(s):

Topology Optimization ◽

Failure Criterion ◽

Load Capacity ◽

Specific Power ◽

Fracture Plane ◽

Fiber Reinforced ◽

Specific Mass ◽

Fiber Fracture ◽

Damage And Fracture ◽

Aero Engine

From Aero Engines of the future it is demanded to provide more power, while the fuel consumption and the mass should decrease. In order to reach the goal of an increasing specific power or a decreasing specific mass, respectively, structural optimization methods, like the topology optimization, find their way into the design process to a greater extent. Additionally one is going to consider more and more fiber reinforced composites as a substitute for titanium alloys in the “cold” structure of the engine. Composite materials offer significant advantages especially concerning the specific mass and the adjustability of their stiffness properties. Unfortunately it is very difficult to predict damage and fracture of such orthotropic materials. The presentation will show the results of a topology optimization of the titanium intermediate-casing of a Rolls-Royce aero engine. Further on the material of the casing will be substituted by a carbon fiber reinforced composite. The fiber orientations and layer thicknesses of the composite are optimized under certain strength constraints, which are described by a modern fracture plane based failure criterion (NASA LaRC04 criterion [6]). Such a failure criterion has a lot of advantages compared to classical ones like Tsai-Hill, Tsai-Wu, ..., which e.g. do not distinguish between fiber and inter-fiber fracture and are therefore not able to predict the type of inter-fiber fracture. Finally the results of the optimization with the current material titanium will be compared to the results of the composite-made intermediate casing in terms of their load capacity and weight.

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Changes in mechanisms and intensity of Western U.S. floods, 1960-2013

10.5194/egusphere-egu21-3816 ◽

2021 ◽

Author(s):

Jessica Fayne ◽

Huilin Huang ◽

Mike Fischella ◽

Yufei Liu ◽

Zhaoxin Ban ◽

...

Keyword(s):

Extreme Precipitation ◽

Large Scale ◽

Critical Factor ◽

Flood Frequency ◽

Atmospheric Rivers ◽

Convective Storms ◽

Noticeable Increase ◽

Complex Interactions ◽

Different Types ◽

The Impact

<p>Extreme precipitation, a critical factor in flooding, has selectively increased with warmer temperatures in the Western U.S. Despite this, the streamflow measurements have captured no noticeable increase in large-scale flood frequency or intensity. As flood studies have mostly focused on specific flood events in particular areas, analyses of large-scale floods and their changes have been scarce. For floods during 1960-2013, we identify six flood generating mechanisms (FGMs) that are prominent across the Western U.S., including atmospheric rivers and non-atmospheric rivers, monsoons, convective storms, radiation-driven snowmelt, and rain-on-snow, in order to identify to what extent different types of floods are changing based on the dominant FGM. The inconsistency between extreme precipitation and lack of flood increase suggests that the impact of climate change on flood risk has been modulated by hydro-meteorological and physiographic processes such as sharp increases in temperature that drive increased evapotranspiration and decreased soil moisture. Our results emphasize the importance of FGMs in understanding the complex interactions of flooding and climatic changes and explain the broad spatiotemporal changes that have occurred across the vast Western U.S. for the past 50 years.</p>

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Numerical and Experimental Study on the Impact of Mild Cold EGR on Exhaust Emissions in a Biodiesel Fueled Diesel Engine

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4051951 ◽

2021 ◽

Author(s):

Alex Oliveira ◽

Junfeng Yang ◽

Jose Sodre

Keyword(s):

Diesel Engine ◽

Fuel Consumption ◽

Exhaust Emissions ◽

Pollutant Emissions ◽

Cylinder Pressure ◽

Nox Formation ◽

Ratio Distribution ◽

Engine Model ◽

Gas Recirculation ◽

The Impact

Abstract This work evaluated the effect of cooled exhaust gas recirculation (EGR) on fuel consumption and pollutant emissions from a diesel engine fueled with B8 (a blend of biodiesel and Diesel 8:92%% by volume), experimentally and numerically. Experiments were carried out on a Diesel power generator with varying loads from 5 kW to 35 kW and 10% of cold EGR ratio. Exhaust emissions (e.g. THC, NOX, CO etc.) were measured and evaluated. The results showed mild EGR and low biodiesel content have minor impact of engine specific fuel consumption, fuel conversion efficiency and in-cylinder pressure. Meanwhile, the combination of EGR and biodiesel reduced THC and NOX up to 52% and 59%, which shows promising effect on overcoming the PM-NOX trade-off from diesel engine. A 3D CFD engine model incorporated with detailed biodiesel combustion kinetics and NOx formation kinetics was validated against measured in-cylinder pressure, temperature and engine-out NO emission from diesel engine. This valid model was then employed to investigate the in-cylinder temperature and equivalence ratio distribution that predominate NOx formation. The results showed that the reduction of NOx emission by EGR and biodiesel is obtained by a little reduction of the local in-cylinder temperature and, mainly, by creating comparatively rich combusting mixture.

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A General Ply Design for Aero Engine Composite Fan Blade

Volume 7A: Structures and Dynamics ◽

10.1115/gt2017-64377 ◽

2017 ◽

Cited By ~ 1

Author(s):

Jiaguangyi Xiao ◽

Yong Chen ◽

Qichen Zhu ◽

Jun Lee ◽

Tingting Ma

Keyword(s):

Composite Laminates ◽

Composite Structures ◽

Stacking Sequence ◽

Composite Blade ◽

Arduous Task ◽

Aero Engine ◽

Margin Of Safety ◽

Fan Blade ◽

The Impact ◽

Ply Orientation

Composite fan blade ply lay-up design, which includes ply drop-off/shuffle design and stacking sequence design, makes fan blade structures different from traditional composite structures. It gives designers more freedom to construct high-quality fan blades. However, contemporary fan blade profiles are quite complex and twisted, and fan blade structures are quite different from regular composite structures such as composite laminates and composite wings. The ply drop-off design of a fan blade, especially for a fully 3D fan blade, is still an arduous task. To meet this challenge, this paper develops a ply lay-up way with the help of a software called Fibersim. The fully 3D fan blade is cut into ply pieces in Fibersim. As a result, an initial ply sequence is created and ply shuffle could revise it. Because of the complexity of ply shuffling, the ply shuffle table developed in this paper mainly refers to the design experience gained from simple plate-like laminate structures and some criterion. Besides, the impact of different ply orientation patterns on the reliability of composite fan blade is studied through static and modal numerical analysis. The results show that this ply lay-up idea is feasible for aero engine composite fan blade. Under the calculated rotating speeds, the ply stacking sequence 4 (i.e.[−45°/0°/+45°/0°] with the outer seven groups are [−45°/0°/−45°/0°]) shows the greatest margin of safety compared with other stacking sequences. Modal analysis shows that plies with different angles could have relatively big different impacts on blades vibration characteristics. The composite fan blade ply design route this paper presents has gain its initial success and the results in this paper might be used as basic references for composite blade initial structural design.

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A mimicking technique of back pressure in the hardware-in-the-loop simulation of a fuel control unit

SIMULATION ◽

10.1177/0037549719873969 ◽

2019 ◽

Vol 96 (4) ◽

pp. 375-385 ◽

Cited By ~ 1

Author(s):

Yuan Yuan ◽

Zhiwen Zhao ◽

Tianhong Zhang

Keyword(s):

Control Unit ◽

Back Pressure ◽

Hardware In The Loop ◽

Fuel System ◽

Working Process ◽

Aero Engine ◽

Aero Engines ◽

Performance Results ◽

The Impact ◽

Hil Simulation

In the hardware-in-the-loop (HIL) simulation of the fuel control unit (FCU) for aero-engines, the back pressure has a great impact on the metered fuel, thus influencing the confidence of the simulation. During the practical working process of an aero-engine, the back pressure of the FCU is influenced by the combined effect of the pressure of the combustion chamber, the resistance of the spray nozzles, and the resistance of the distribution valve. There is a need to study the the mimicking technique of FCU back pressure. This paper models the fuel system of an aero-engine so as to reveal the impact of FCU back pressure on the metered fuel and come up with a scheme to calculate the equivalent FCU back pressure. After analyzing the requirements for mimicking the pressure, an automatic regulating facility is designed to adjust the FCU back pressure in real time. Finally, experiments are carried out to verify its performance. Results show that the mimicking technique of back pressure is well suited for application in HIL simulation. It is able to increase the confidence of the simulation and provide guidance to the implementation of mimicking the FCU back pressure.

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Standardization of complementary work time in timber harvesting processes

Folia Forestalia Polonica ◽

10.2478/ffp-2020-0025 ◽

2020 ◽

Vol 62 (4) ◽

pp. 258-269

Author(s):

Krzysztof Kamiński ◽

Grzegorz Szewczyk ◽

Janusz Kocel

Keyword(s):

Accurate Determination ◽

Timber Harvesting ◽

Time Structure ◽

Working Environment ◽

Work Time ◽

Work Shift ◽

Machine Technology ◽

Working Day ◽

Technology Level ◽

The Impact

AbstractOne of the essential elements of work technology assessment is task performance time. In the working day structure, production times are crucial; however, under certain conditions, complementary work times can have a share of up to 30%. Accurate determination of the time structure of a work shift is very time consuming and requires time measurements using the methods of cumulative timing or snapshot observations. For this reason, the overall share of complementary work times in a work shift is usually estimated roughly, equally for all timber harvesting conditions. The aim of this study was to determine the impact of selected working environment factors on the share of complementary work times in a work shift, in technologies on the manual-machine and the machine levels. The analyses were carried out in 33 forest districts of the Regional Directorate of State Forests in Wrocław. Among forest contractors, surveys were carried out to analyse the time structure of a working day. For each forest district, analyses of environmental factors potentially relevant to the share of complementary work times in a work shift were carried out; these included field features, dispersion of stands, features of timber, area accessibility. The total share of complementary work times in the machine-level technology variant amounted to approx. 40% and was higher than the manual-machine technological variant, where this share amounted to approx. 35%. The models developed for standardization of the share of variability of complementary work times, in the case of the manual-machine technology level, took into account the share of timber assortments with the length of over 2.5 m as well as the share of upland and mountain sites. In the case of timber harvesting at the machine technology level, the standardization model included as significant the factors such as the share of coniferous forest sites, the number of forest complexes with an area of over 100 hectares, and the total length of roads. Therefore, the above features could be selected as decisive for the share of the complementary work time category out of the full set of environmental variables taken into consideration in the estimation of the time-consumption of timber harvesting processes.

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