Aircraft Engine Technology for Green Aviation to Reduce Fuel Burn

Aviation faces increasing pressure not only to reduce fuel burn, and; therefore, CO2 emissions, but also to provide technical solutions for an overall climate impact minimization. To combine both, a concept for the enhancement of an aircraft engine by steam injection with inflight water recovery is being developed. The so-called Water-Enhanced Turbofan (WET) concept promises a significant reduction of CO2 emissions, NOx emissions, and contrail formation. Representative missions for an A320-type aircraft using the proposed new engine were calculated. Applying a first-order one-dimensional climate assessment prospects the reduction of more than half of the Global Warming Potential over one hundred years, compared to an evolutionarily improved aero-engine. If CO2-neutrally produced sustainable aviation fuels are used, climate impact could be reduced by 93% compared to today’s aircraft. The evaluation is a first estimate of effects based on preliminary design studies and should provide a starting point for discussion in the scientific community, implying the need for research, especially on the formation mechanisms and radiation properties of potential contrails from the comparatively cold exhaust gases of the WET engine.

Download Full-text

Cycle Optimization Potential of Composite Cycle and Turbocompound Aero-Engines

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4046820 ◽

2020 ◽

Vol 142 (6) ◽

Author(s):

Felix Klein ◽

Stephan Staudacher

Keyword(s):

Gas Turbine ◽

Gas Turbines ◽

Pressure Ratio ◽

Exchange Process ◽

Aircraft Engine ◽

Time Frame ◽

Fuel Burn ◽

Component Efficiency ◽

Low Efficiency ◽

Aero Engines

Abstract Fair comparison of future aircraft engine concepts requires the assumption of similar technological risk and a transparent book keeping of losses. A 1000 km and a 7000 km flight mission of a single-aisle airplane similar to the Aribus A321neo LR have been used to compare composite cycle engines, turbocompound engines and advanced gas turbines as potential options for an entry-into-service time frame of 2050+. A 2035 technology gas turbine serves as reference. The cycle optimization has been carried out with a peak pressure ratio of 250 and a maximum cycle temperature of 2200 K at cruise as boundary conditions. With the associated heat loss and the low efficiency of the gas exchange process limiting piston component efficiency, the cycle optimization filtered out composite cycle concepts. Taking mission fuel burn (MFB) as the most relevant criterion, the highest MFB reduction of 13.7% compared to the 2035 reference gas turbine is demonstrated for an air-cooled turbocompound concept with additional combustion chamber. An intercooled, hectopressure gas turbine with pressure gain combustion achieves 20.6% reduction in MFB relative to the 2035 reference gas turbine.

Download Full-text

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

Transportation Research Record Journal of the Transportation Research Board ◽

10.1177/0361198118780876 ◽

2018 ◽

Vol 2672 (29) ◽

pp. 1-11 ◽

Cited By ~ 1

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.

Download Full-text

More Electric Engine Architecture for Aircraft Engine Application

Volume 3: Controls, Diagnostics and Instrumentation; Education; Electric Power; Microturbines and Small Turbomachinery; Solar Brayton and Rankine Cycle ◽

10.1115/gt2011-46765 ◽

2011 ◽

Cited By ~ 8

Author(s):

Noriko Morioka ◽

Hitoshi Oyori ◽

Daiki Kakiuchi ◽

Kanji Ozawa

Keyword(s):

Fault Tolerant ◽

Fuel Efficiency ◽

Reducing Power ◽

Aircraft Engine ◽

Engine Control ◽

Pump System ◽

Power Extraction ◽

Engine Control System ◽

Fuel Burn ◽

Electric Engine

This paper describes the system design and evaluation of a noble MEE (More Electric Engine) system. The results show that the proposed MEE system can significantly reduce the fuel burn of engines and CO2 emissions from aircraft and also improve the safety, reliability and maintainability of engines. The MEE is advanced engine control technology utilizing recent innovations in electrical motors, motor controllers and power electronics. It replaces conventional engine accessories, such as AGB (Accessory Gear Box)-driven pumps, hydraulic actuators with electrical pumps and EMAs (Electro-Mechanical Actuators), which are powered by generators. The first step of the MEE is supposed to be the motor-driven fuel pump system, which can improve engine efficiency by reducing power extraction from the engine and eliminating ACOCs (Air-Cooled Oil Coolers) which worsen fuel efficiency by wasting fan discharge air. The goal of the MEE consists of eliminating the heavy AGB via electrical accessories and an engine-embedded starter/generator. The incorporation of a unique redundant Active-Active control architecture and a fault-tolerant design for the dual motor system successfully achieves a highly reliable and complete one fail operational/two fail safe engine control system.

Download Full-text

Numerical Simulation of Propulsion System Integration for Very High Bypass Ratio Engines

Volume 1: Aircraft Engine; Ceramics; Coal, Biomass and Alternative Fuels; Controls, Diagnostics and Instrumentation ◽

10.1115/gt2012-68908 ◽

2012 ◽

Cited By ~ 1

Author(s):

Thierry Sibilli ◽

Mark Savill ◽

Vishal Sethi ◽

David MacManus ◽

Andrew M. Rolt

Keyword(s):

System Integration ◽

New Technologies ◽

Engine Performance ◽

Aircraft Design ◽

Aircraft Engine ◽

Fuel Burn ◽

Active Core ◽

Core Concepts ◽

Work Programme ◽

Bypass Ratio

Due to a trend towards Ultra High Bypass Ratio engines, confirmed in projects like NEWAC (New Aero Engine Core Concepts, an European Sixth Frame Work Programme) the corresponding engine/airframe interference is becoming a key aspect in aircraft design. Therefore detailed aerodynamic investigations are required to evaluate the real benefits of these new technologies. The work presented in this paper is to perform these investigations for two typical twin-engine/low-wing transports, using Computational Fluid Dynamics, in order to create a useful integration module for the in-house aircraft/engine performance software TERA2020 (Techno-economic Environmental and Risk Assessment for 2020). The paper presents results for two NEWAC engines: Intercooled Core Long Range (IC L/R) and the Active Core Short Range (AC S/R). The main results show that the engine horizontal positioning can influence mission fuel burn by up to 6.4% for AC S/R and 3.7% for IC L/R respectively.

Download Full-text

Physics-Based Thermal Model for Power Gearboxes in Geared Turbofan Engines

Volume 1: Aircraft Engine; Fans and Blowers ◽

10.1115/gt2020-14637 ◽

2020 ◽

Author(s):

Soheil Jafari ◽

Theoklis Nikolaidis ◽

Albert S. J. van Heerden ◽

Craig P. Lawson ◽

David Bosak

Keyword(s):

Heat Loss ◽

Waste Heat ◽

Methodological Approach ◽

Engine Performance ◽

Aircraft Engine ◽

Mechanical Efficiency ◽

Total Power ◽

Thermal Loads ◽

Loss Mechanism ◽

Fuel Burn

Abstract Ultra-High Bypass Ratio Geared (UHBRG) turbofan technology allows a significant reduction in fuel burn, noise and emissions — key metrics for aircraft engine performance. However, one of the main challenges in this technology is the large amount of waste heat generated by the Power Gearbox (PGB). Therefore, having a practical tool for precise prediction of the PGB-generated thermal loads in UHBRGs is becoming a necessity. Such a tool would assist in analyzing engine performance, as well as ensuring that engine physical limitations/restrictions are not breached (e.g. over-temperature in fuel and oil, cocking, etc.). This paper presents a methodological approach to mathematically model the waste heat generated by a PGB on a UHBRG for different points on a typical flight profile. To do this, the total power loss in a PGB system is firstly defined as the summation of load-dependent and load-independent losses. Physics-based equations for each heat loss mechanism are introduced and, through a combination of the associated equations, a simulation model for the thermal loads calculation in PGBs is developed. In addition, the heat losses and efficiency of the PGB has been analyzed across a simulated flight. The developed PGB model calculates the main power losses generated in a gear reduction system of a turbofan engine. It is found that in a typical flight, the heat loss generated by the PGB can reach about 80% of the total waste heat generated by the engine. The values of the mechanical efficiency calculated by the tool at different flight points are above 97% which is in good agreement with publicly available data for planetary gearboxes. This tool is intended to be utilized by engine thermal management system designers to predict and analyze the heat loads generated by the PGB at different flight conditions.

Download Full-text

The Engineering Doctorate — An ‘Enhanced’ Doctoral Programme for Engineers Incorporating Business Decision-Making Skills: A Gas-Turbine Engineering Perspective

Volume 4: Manufacturing Materials and Metallurgy; Ceramics; Structures and Dynamics; Controls, Diagnostics and Instrumentation; Education ◽

10.1115/2000-gt-0582 ◽

2000 ◽

Cited By ~ 1

Author(s):

Paul C. Ivey ◽

Michael L. Sanderson ◽

Vivien Morris ◽

Derek G. Ferguson

Keyword(s):

Decision Making ◽

Gas Turbine ◽

Aircraft Engine ◽

Product Launch ◽

Engine Fuel ◽

Design Development ◽

Business Decision ◽

Course Structure ◽

Fuel Burn ◽

The Uk

This paper describes a new UK initiative in the post graduate education of Engineers. The new ‘enhanced’ degree of Engineering Doctorate educates graduate Engineers in their respective technical disciplines whilst at the same time integrating the world of commerce and business into the technical decision making process. The paper describes the initial candidate selection methodology, project selection, course structure, assessment, thesis structure and outputs. The advantages of this enhanced postgraduate training are demonstrated, as are the objectives for the UK in adopting such a scheme. An example is presented from a joint Rolls Royce / Cranfield case study of the Design, Development and Product launch of a new type of Gas Turbine Instrumentation. This is set in a Gas Turbine Engineering perspective, in particular the consideration of active control of compressor surge to benefit aircraft engine fuel burn and increased flight range.

Download Full-text

High-Temperature Instability of A Cr2Nb-Nb(Cr) Microlaminate Composite

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100164337 ◽

1996 ◽

Vol 54 ◽

pp. 374-375

Author(s):

M. Larsen ◽

R.G. Rowe ◽

D.W. Skelly

Keyword(s):

Heat Treatment ◽

Solid Solution ◽

High Temperature ◽

Elevated Temperatures ◽

Aircraft Engine ◽

Lattice Parameter ◽

Microstructural Stability ◽

Elevated Temperature Strength ◽

Cross Sectional ◽

Bcc Structure

Microlaminate composites consisting of alternating layers of a high temperature intermetallic compound for elevated temperature strength and a ductile refractory metal for toughening may have uses in aircraft engine turbines. Microstructural stability at elevated temperatures is a crucial requirement for these composites. A microlaminate composite consisting of alternating layers of Cr2Nb and Nb(Cr) was produced by vapor phase deposition. The stability of the layers at elevated temperatures was investigated by cross-sectional TEM.The as-deposited composite consists of layers of a Nb(Cr) solid solution with a composition in atomic percent of 91% Nb and 9% Cr. It has a bcc structure with highly elongated grains. Alternating with this Nb(Cr) layer is the Cr2Nb layer. However, this layer has deposited as a fine grain Cr(Nb) solid solution with a metastable bcc structure and a lattice parameter about half way between that of pure Nb and pure Cr. The atomic composition of this layer is 60% Cr and 40% Nb. The interface between the layers in the as-deposited condition appears very flat (figure 1). After a two hour, 1200 °C heat treatment, the metastable Cr(Nb) layer transforms to the Cr2Nb phase with the C15 cubic structure. Grain coarsening occurs in the Nb(Cr) layer and the interface between the layers roughen. The roughening of the interface is a prelude to an instability of the interface at higher heat treatment temperatures with perturbations of the Cr2Nb grains penetrating into the Nb(Cr) layer.

Download Full-text