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

2012 ◽  
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.

Modeling Contra-Rotating Turbomachinery Components for Engine Performance Simulations: The Geared Turbofan With Contra-Rotating Core Case

2012 ◽  
Vol 134 (11) ◽  
Author(s):  
A. Alexiou ◽  
I. Roumeliotis ◽  
N. Aretakis ◽  
A. Tsalavoutas ◽  
K. Mathioudakis
Keyword(s):  
Three Dimensional ◽  
Engine Performance ◽  
Performance Model ◽  
Speed Ratio ◽  
The Core ◽  
Fuel Burn ◽  
Core Concepts ◽  
Additional Table ◽  
Cooling Air Flow ◽  
Cooling Air

This paper presents a method of modeling contra-rotating turbomachinery components for engine performance simulations. The first step is to generate the performance characteristics of such components. In this study, suitably modified one-dimensional mean line codes are used. The characteristics are then converted to three-dimensional tables (maps). Compared to conventional turbomachinery component maps, the speed ratio between the two shafts is included as an additional map parameter and the torque ratio as an additional table. Dedicated component models are then developed that use these maps to simulate design and off-design operation at the component and engine levels. Using this approach, a performance model of a geared turbofan with a contra-rotating core (CRC) is created. This configuration was investigated in the context of the European program “NEW Aero-Engine Core Concepts” (NEWAC). The core consists of a seven-stage compressor and a two-stage turbine without interstage stators and with successive rotors running in the opposite direction through the introduction of a rotating outer spool. Such a configuration results in a reduced parts count, length, weight, and cost of the entire high pressure (HP) system. Additionally, the core efficiency is improved due to reduced cooling air flow requirements. The model is then coupled to an aircraft performance model and a typical mission is carried out. The results are compared against those of a similar configuration employing a conventional core and identical design point performance. For the given aircraft-mission combination and assuming a 10% engine weight saving when using the CRC arrangement over the conventional one, a total fuel burn reduction of 1.1% is predicted.

Thrust Reverser for a Separate Exhaust High Bypass Ratio Turbofan Engine and its Effect on Aircraft and Engine Performance

2011 ◽  
Author(s):  
Tashfeen Mahmood ◽  
Anthony Jackson ◽  
Vishal Sethi ◽  
Pericles Pilidis
Keyword(s):  
Engine Performance ◽  
Aircraft Engine ◽  
Performance Characteristics ◽  
System Level ◽  
Performance Models ◽  
Turbofan Engine ◽  
Engine Model ◽  
Rate Deceleration ◽  
Thrust Reverser ◽  
Bypass Ratio

This paper discusses thrust reversing techniques for a separate exhaust high bypass ratio turbofan engine and its effect on aircraft and engine performance. Cranfield University is developing suitable thrust reverser performance models. These thrust reverser performance models will subsequently be integrated within the TERA (Techno-economic Environmental Risk Analysis) architecture thereby allowing for more detailed and accurate representations of aircraft and engine performance during the landing phase of a typical civil aircraft mission. The turbofan engine chosen for this study was CUTS_TF (Cranfield University Twin Spool Turbofan) which is similar to the CFM56-5B4 engine and the information available in the public domain is used for the engine performance analysis along with the Gas Turbine Performance Software, ‘GasTurb 10’ [1]. The CUTEA (Cranfield University Twin Engine Aircraft) which is similar to the Airbus A320 is used alongside with the engine model for the thrust reverser performance calculations. The aim of this research paper is to investigate the effects on aircraft and engine performance characteristics due to the pivoting door type thrust reverser deployment. The paper will look into the overall engine performance characteristics and how the engine components get affected when the thrust reversers come into operation. This includes the changes into the operating point of fan, booster, HP compressor, HP turbine, LP turbine, bypass nozzle and core nozzle. Also, thrust reverser performance analyses were performed (at aircraft/engine system level) by varying the reverser exit area by ± 5% and its effect on aircraft deceleration rate, deceleration time and landing distances were observed.

Modelling Contra-Rotating Turbomachinery Components for Engine Performance Simulations: The Geared Turbofan With Contra-Rotating Core Case

2012 ◽  
Author(s):  
A. Alexiou ◽  
I. Roumeliotis ◽  
N. Aretakis ◽  
A. Tsalavoutas ◽  
K. Mathioudakis
Keyword(s):  
Three Dimensional ◽  
Engine Performance ◽  
Performance Model ◽  
Speed Ratio ◽  
The Core ◽  
Fuel Burn ◽  
Core Concepts ◽  
Additional Table ◽  
Cooling Air Flow ◽  
Cooling Air

This paper presents a method of modelling contra-rotating turbomachinery components for engine performance simulations. The first step is to generate the performance characteristics of such components. In this study, suitably modified one-dimensional mean line codes are used. The characteristics are then converted to three-dimensional tables (maps). Compared to conventional turbomachinery component maps, the speed ratio between the two shafts is included as an additional map parameter and the torque ratio as an additional table. Dedicated component models are then developed that use these maps to simulate design and off-design operation at component and engine level. Using this approach, a performance model of a geared turbofan with a Contra-Rotating Core (CRC) is created. This configuration was investigated in the context of the European program NEWAC (NEW Aero-engine core Concepts). The core consists of a seven-stage compressor and a two-stage turbine without inter-stage stators and with successive rotors running in opposite direction through the introduction of a rotating outer spool. Such a configuration results in reduced parts count, length, weight and cost of the entire HP system. Additionally, the core efficiency is improved due to reduced cooling air flow requirements. The model is then coupled to an aircraft performance model and a typical mission is carried out. The results are compared against those of a similar configuration employing a conventional core and identical design point performance. For the given aircraft-mission combination and assuming a 10% engine weight saving when using the CRC arrangement over the conventional one, a total fuel burn reduction of 1.1% is predicted.

scholarly journals Scale effects on conventional and intercooled turbofan engine performance

2017 ◽  
Vol 121 (1242) ◽  
pp. 1162-1185 ◽  
Author(s):  
Andrew Rolt ◽  
Vishal Sethi ◽  
Florian Jacob ◽  
Joshua Sebastiampillai ◽  
Carlos Xisto ◽  
...  
Keyword(s):  
Thermal Efficiency ◽  
New Technologies ◽  
Scale Effects ◽  
Engine Performance ◽  
Specific Power ◽  
Core Size ◽  
Core Mass ◽  
Horizon 2020 ◽  
Fuel Burn ◽  
Aero Engines

ABSTRACTNew commercial aero engines for 2050 are expected to have lower specific thrusts for reduced noise and improved propulsive efficiency, but meeting the ACARE Flightpath 2050 fuel-burn and emissions targets will also need radical design changes to improve core thermal efficiency. Intercooling, recuperation, inter-turbine combustion and added topping and bottoming cycles all have the potential to improve thermal efficiency. However, these new technologies tend to increase core specific power and reduce core mass flow, giving smaller and less efficient core components. Turbine cooling also gets more difficult as engine cores get smaller. The core-size-dependent performance penalties will become increasingly significant with the development of more aerodynamically efficient and lighter-weight aircraft having lower thrust requirements. In this study the effects of engine thrust and core size on performance are investigated for conventional and intercooled aeroengine cycles. Large intercooled engines could have 3%–4% SFC improvement relative to conventional cycle engines, while smaller engines may only realize half of this benefit. The study provides a foundation for investigations of more complex cycles in the EU Horizon 2020 ULTIMATE programme.

scholarly journals Ideal Power Output — An Alternative Aircraft Engine Performance Comparator

1997 ◽  
Author(s):  
Marvin F. Schmidt ◽  
Christopher M. Norden ◽  
Jeffrey M. Stricker
Keyword(s):  
Gas Turbine ◽  
Power Output ◽  
State Of The Art ◽  
Pressure Ratio ◽  
Engine Performance ◽  
Aircraft Engine ◽  
The State ◽  
Power Cycle ◽  
Shaft Power ◽  
Bypass Ratio

The gas turbine is applied in four basic configurations; the turbojet, the turbofan, the turboprop and the turboshaft. Comparisons of the performance of these various configurations is difficult since they convert the energy to different forms, i.e. thrust or shaft power. Cycle variables which do not necessarily constitute advancements in the state-of-the-art such as bypass ratio and fan pressure ratio can have a profound effect on thrust and shaft power. Differences in flight speed and altitude capability further confound the comparisons. What is required is a comparison methodology that removes all of these variables and yet puts all the various types of engines on an equitable basis. This paper will provide such a comparison tool. All turbomachinery, regardless of configuration, can be compared with this method.

scholarly journals Modeling Geared Turbofan and Open Rotor Engine Performance for Year-2050 Long-Range and Short-Range Aircraft

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Francesco S. Mastropierro ◽  
Joshua Sebastiampillai ◽  
Florian Jacob ◽  
Andrew Rolt
Keyword(s):  
Short Range ◽  
Pressure Ratio ◽  
Engine Performance ◽  
Optimized Design ◽  
Fuel Burn ◽  
Medium Range ◽  
Open Rotor ◽  
And Performance ◽  
Year 2000 ◽  
Bypass Ratio

Abstract This paper provides design and performance data for two envisaged year-2050 engines: a geared high bypass turbofan for intercontinental missions and a contra-rotating pusher open rotor targeting short to medium range aircraft. It defines component performance and cycle parameters, general arrangements, sizes, and weights. Reduced thrust requirements reflect expected improvements in engine and airframe technologies. Advanced simulation platforms have been developed to model the engines and details of individual components. The engines are optimized and compared with “baseline” year-2000 turbofans and an anticipated year-2025 open rotor to quantify the relative fuel-burn benefits. A preliminary scaling with year-2050 “reference” engines, highlights tradeoffs between reduced specific fuel consumption (SFC) and increased engine weight and diameter. These parameters are converted into mission fuel burn variations using linear and nonlinear trade factors (NLTF). The final turbofan has an optimized design-point bypass ratio (BPR) of 16.8, and a maximum overall pressure ratio (OPR) of 75.4, for a 31.5% TOC thrust reduction and a 46% mission fuel burn reduction per passenger kilometer compared to the respective “baseline” engine–aircraft combination. The open rotor SFC is 9.5% less than the year-2025 open rotor and 39% less than the year-2000 turbofan, while the TOC thrust increases by 8% versus the 2025 open rotor, due to assumed increase in passenger capacity. Combined with airframe improvements, the final open rotor-powered aircraft has a 59% fuel-burn reduction per passenger kilometer relative to its baseline.

scholarly journals Multi-Fidelity Design Optimization of a Long-Range Blended Wing Body Aircraft with New Airframe Technologies

Aerospace ◽  
2020 ◽  
Vol 7 (7) ◽  
pp. 87
Author(s):  
Stanislav Karpuk ◽  
Yaolong Liu ◽  
Ali Elham
Keyword(s):  
Long Range ◽  
New Technologies ◽  
Active Flow Control ◽  
Preliminary Investigation ◽  
Aircraft Design ◽  
Fuel Burn ◽  
Aircraft Fuel ◽  
Computational Fluid Dynamics Cfd ◽  
Blended Wing Body ◽  
Active Flow

The German Cluster of Excellence SE²A (Sustainable and Energy Efficient Aviation) is established in order to investigate the influence of game-changing technologies on the energy efficiency of future transport aircraft. In this paper, the preliminary investigation of the four game-changing technologies active flow control, active load alleviation, boundary layer ingestion, and novel materials and structure concepts on the performance of a long-range Blended Wing Body (BWB) aircraft is presented. The BWB that was equipped with the mentioned technologies was designed and optimized using the multi-fidelity aircraft design code SUAVE with a connection to the Computational Fluid Dynamics (CFD) code SU2. The conceptual design of the BWB aircraft is performed within the SUAVE framework, where the influence of the new technologies is investigated. In the second step, the initially designed BWB aircraft is improved by an aerodynamic shape optimization while using the SU2 CFD code. In the third step, the performance of the optimized aircraft is evaluated again using the SUAVE code. The results showed more than 60% reduction in the aircraft fuel burn when compared to the Boeing 777.

scholarly journals Modelling Geared Turbofan and Open Rotor Engine Performance for Year-2050 Long-Range and Short-Range Aircraft

2019 ◽  
Author(s):  
Joshua Sebastiampillai ◽  
Florian Jacob ◽  
Francesco S. Mastropierro ◽  
Andrew Rolt
Keyword(s):  
State Of The Art ◽  
Pressure Ratio ◽  
Engine Performance ◽  
Fuel Burn ◽  
Trade Offs ◽  
Medium Range ◽  
Open Rotor ◽  
And Performance ◽  
Year 2000 ◽  
Bypass Ratio

Abstract The paper provides design and performance data for two envisaged year-2050 state-of-the-art engines: a geared high bypass turbofan for intercontinental missions and a contra-rotating pusher open rotor targeting short to medium range aircraft. It defines component performance and cycle parameters, general powerplant arrangements, sizes and weights. Reduced thrust requirements for future aircraft reflect expected improvements in engine and airframe technologies. Advanced simulation platforms have been developed, using the software PROOSIS, to model the engines and details of individual components, including custom elements for the open rotor engine. The engines are optimised and compared with ‘baseline’ year-2000 turbofans and an anticipated year-2025 entry-into-service open rotor to quantify the relative fuel-burn benefits. A preliminary scaling with non-optimised year-2050 ‘reference’ engines, based on Top-of-Climb (TOC) thrust and bypass ratio, highlights the trade-offs between reduced specific fuel consumption (SFC) and increased weight and engine diameter. These parameters are then converted into mission fuel burn using linear and non-linear trade factors from aircraft models. The final turbofan has an optimised design-point bypass ratio (BPR) of 16.8, and a maximum overall pressure ratio (OPR) of 75.4 for a 31.5% TOC thrust reduction and a 46% mission fuel burn reduction per passenger kilometre compared to the respective year-2000 baseline engine and aircraft combination. The final open rotor SFC is 9.5% less than the year-2025 open rotor and 39% less than the year-2000 turbofan, while the TOC thrust increases by 8% versus the 2025 open rotor, due to assumed increase in aircraft passenger capacity. Combined with airframe improvements, the final open rotor-powered aircraft has a 59% fuel-burn reduction per passenger kilometre relative to its year-2000 baseline.

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

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.

Short and Long Range Mission Analysis for a Geared Turbofan With Active Core Technologies

2010 ◽  
Author(s):  
A. Alexiou ◽  
N. Aretakis ◽  
I. Roumeliotis ◽  
K. Mathioudakis
Keyword(s):  
Long Range ◽  
Gas Turbines ◽  
New Technology ◽  
Engine Performance ◽  
Mission Analysis ◽  
Active Core ◽  
Core Concepts ◽  
European Program ◽  
Year 2000 ◽  
Engine Concept

A novel engine concept, for reducing the environmental impact of gas turbines, is the Geared Turbofan with Active Core technologies (GTAC), investigated in the context of the European program NEWAC (New Aero Engine Core Concepts). Two performance models of this engine are created for short and long range aircraft applications and matched to manufacturer specifications. The engine performance data are used in a mission analysis module simulating typical aircraft applications. Compared to missions using Year 2000 in service engines, the results show a significant reduction in fuel consumption and noise levels. A significant reduction in NOx emissions requires the application of new technology combustor designs as developed e.g. in NEWAC.

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