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

Author(s):  
Tashfeen Mahmood ◽  
Anthony Jackson ◽  
Syed H. Rizvi ◽  
Pericles Pilidis ◽  
Mark Savill ◽  
...  

This paper discusses thrust reverser techniques for a mixed exhaust high bypass ratio turbofan engine and its effect on aircraft and engine performance. The turbofan engine chosen for this study was CUTS_TF (Cranfield University Three Spool Turbofan) which is similar to Rolls-Royce TRENT 772 engine and the information available for this engine in the public domain is used for the engine performance analysis along with the Gas Turbine Performance Software, GasTurb 10. The CUTEA (Cranfield University Twin Engine Aircraft) which is similar to the Airbus A330 is used along side with the engine model for the thrust reverser performance calculations. The aim of this research paper is to investigate the effects on mixed exhaust engine performance due to the pivoting door type thrust reverser deployment. The paper looks into the engine off-design performance characteristics and how the engine components get affected when the thrust reverser come into operation. This includes the changes into the operating point of fan, IP compressor, HP compressor, HP turbine, IP turbine, LP turbine and the engine exhaust nozzle. Also, the reverser deployment effect on aircraft, deceleration time and landing distances are discussed.

Author(s):  
Tashfeen Mahmood ◽  
Anthony Jackson ◽  
Vishal Sethi ◽  
Pericles Pilidis

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.


Author(s):  
Enaut Gonzalez-Ruiz ◽  
Tashfeen Mahmood ◽  
Vishal Sethi ◽  
Pericles Pilidis

Concerns for ecological aviation products and the objective of reducing pollutants to meet ACARE (Advisory Council for Aeronautics Research in Europe) targets address, among other initiatives, the necessity of reducing the overall weight of the aircraft. One way of dealing with the problem of aircraft weight is by investigating thrust reversers. Reducing the reverser weight will have favourable effects on fuel consumption and CO2 emissions. This paper discusses the target type thrust reverser concept. This concept was proposed by NASA and has a potential of reducing the reverser weight on future high bypass ratio turbofan engines. A feasibility study of the annular target thrust reverser in terms of engine performance and reverse thrust achieved was carried out. It comprises 2D CFD analyses of the thrust reverser and the effect of the reverser on the engine performance for different deflector configurations. The turbofan engine chosen for this study is CUTS_TF (Cranfield University Twin Spool Turbo Fan) which is similar to the GE90-85B and the information available in the public domain [1] [2] is used for the engine performance analysis along with the gas turbine performance software, GasTurb 10 [3]. CFD analyses were performed using the FLUENT software [4] to investigate the thrust reverser flow dynamics at landing at maximum reverse thrust.


Author(s):  
M. S. Zawislak ◽  
D. J. Cerantola ◽  
A. M. Birk

A high bypass ratio turbofan engine capable of powering the Boeing 757 was considered for thrust and drag analysis. A quasi-2D engine model applying the fundamental thermodynamics conservation equations and practical constraints determined engine performance and provided cross-sectional areas in the low-pressure system. Coupled with suggestions on boat-tail angle and curvature from literature, a representative bypass duct and primary exhaust nozzle was created. 3D steady-RANS simulations using Fluent® 18 were performed on a 1/8th axisymmetric section of the geometry. A modified 3D fan zone model forcing radial equilibrium was used to model the fan and bypass stator. Takeoff speed and cruise operating conditions were modeled and simulated to identify changes in thrust composition and intake sensitivity. Comparison between net thrust predictions by the engine model and measured in CFD were within grid uncertainty and model sensitivity at cruise. Trends observed in a published database were satisfied and calculations coincided with GasTurb™ 8.0. Verification of thrust in this manner gave confidence to the aerodynamic performance prediction of this modest CFD. Obtaining a baseline bypass design would allow rapid testing of aftermarket components and integration techniques in a realistic flow-field without reliance on proprietary engine data.


Author(s):  
Stanislaus Reitenbach ◽  
Alexander Krumme ◽  
Thomas Behrendt ◽  
Markus Schnös ◽  
Thomas Schmidt ◽  
...  

The purpose of this paper is to present a multidisciplinary predesign process and its application to three aero-engine models. First, a twin spool mixed flow turbofan engine model is created for validation purposes. The second and third engine models investigated comprise future engine concepts: a counter rotating open rotor (CROR) and an ultrahigh bypass turbofan. The turbofan used for validation is based on publicly available reference data from manufacturing and emission certification. At first, the identified interfaces and constraints of the entire predesign process are presented. An important factor of complexity in this highly iterative procedure is the intricate data flow, as well as the extensive amount of data transferred between all involved disciplines and among different fidelity levels applied within the design phases. To cope with the inherent complexity, data modeling techniques have been applied to explicitly determine required data structures of those complex systems. The resulting data model characterizing the components of a gas turbine and their relationships in the design process is presented in detail. Based on the data model, the entire engine predesign process is presented. Starting with the definition of a flight mission scenario and resulting top level engine requirements, thermodynamic engine performance models are developed. By means of these thermodynamic models, a detailed engine component predesign is conducted. The aerodynamic and structural design of the engine components are executed using a stepwise increase in level of detail and are continuously evaluated in context of the overall engine system.


Author(s):  
Hakan Aygun ◽  
Onder Turan

Abstract This study focuses on for a PW4000 high-bypass turbofan engine using energy, exergo-sustainable and performance viewpoint. For this aim, irreversibility and performance analyses are firstly performed for five main engine components at ≈260 kN maximum take-off thrust force. Besides, overall efficiency of the turbofan is determined to be 33 %, while propulsive and thermal efficiency of the turbofan are 72 % and 46 % respectively at 0.8 M and 288.15 K flight conditions. Secondly, calculation component-based exergetic assessment is carried out using exergetic indicators. According to the calculation, the exergetic efficiency of the engine is 32 %, while its waste exergy ratio is 0.678. Furthermore, exergetic sustainability measure is obtained as 0.473, while enviromental effect factor is 2.112. These indicators are also anticipated to help comprehend the connection between engine performance parameters and worldwide dimensions such as environmental effect and sustainable growth.


Author(s):  
Julien Pilet ◽  
Jean-Loi¨c Lecordix ◽  
Nicolas Garcia-Rosa ◽  
Roger Bare`nes ◽  
Ge´rard Lavergne

This paper presents a fully-coupled zooming approach for the performance simulation of modern very high bypass ratio turbofan engines developed by Snecma. This simulation is achieved by merging detailed 3D simulations and map component models into a unified representation of the whole engine. Today’s state-of-the-art engine cycle analysis are commonly based on component mapping models which enable component interactions to be considered, while CFD simulations are carried out separately and therefore overlook those interactions. With the methodology discussed in this paper, the detailed analysis of an engine component is no longer considered apart, but directly within the whole engine performance model. Moreover, all links between the 3D simulation and overall engine models have been automated making this zooming simulation fully-integrated. The simulation uses the PROOSIS propulsion object-oriented simulation software developed by Empresarios Agrupados for whole engine cycle analysis and the computational fluid dynamics (CFD) code CEDRE developed by ONERA for the high fidelity 3-D component simulations. The whole engine model is created by linking component models through their communication ports in a graphical user-friendly interface. CFD simulated component models have been implemented in PROOSIS libraries already providing mapped components. Simple averaging techniques have been developed to handle 3D-to-0D data exchange. Boundary conditions of the whole engine model remain the same as for the typical 0-D engine cycle analysis while those of the 3-D simulations are automatically given by PROOSIS to CEDRE. This methodology has been applied on an advanced very high bypass ratio engine developed by Price Induction. The proposed zooming approach has been performed on the fan stage when simulating Main Design Point as well as severe case of off-design conditions such as wind-milling. The results have been achieved within the same time frame of a typical CFD fully-converged calculation. A detailed comparison with upcoming test results will provide a first validation of the methodology and will be presented in a future paper.


1978 ◽  
Author(s):  
M. Kohzu ◽  
H. Chinone ◽  
M. Miyake ◽  
K. Murashima ◽  
K. Yamanaka ◽  
...  

A research program of low bypass ratio small front fan engines has been in process at Third Research Center of Technical Research and Development Institute of Japan Defence Agency since 1975. The final target of this program is the development of the propulsion engine for the high subsonic small aircraft. As the first phase of this program, the bench test engine XF3-1 was manufactured and the basic studies of the overall engine matching performance and the effect of each component on the engine performance have been carried out. This paper describes the XF3-1 engine, reviews the status of the research and presents the major engineering progress attained through the research.


Author(s):  
Min-Su Choi ◽  
In-Shik Kang ◽  
Jin-Shik Lim ◽  
Yong-Shik Hong

The windmilling characteristics of twin-spool, high bypass ratio turbofan engine have been analyzed. This analysis is an extension of the previously reported analysis for a single-spool turbojet engine. As before, the aerodynamic performances of engine components are determined by incorporating the available cascade loss correlations. For a given flight condition, the steady-state windmilling conditions are determined by iteratively balancing the mass flow rate and angular momentum through the two spools. Compared to the turbojet analysis, the new analysis requires determination of bypass ratio and work split between the two spools. Some of the calculation results have been compared against the limited data available for a CF-6 engine, and the two show good agreement. The present method is thus shown to be capable in predicting turbofan engine’s windmilling characteristics during its design stage.


Author(s):  
Martin Dodds ◽  
Pericles Pilidis

An investigation was conducted to examine the effects of a variable flow low pressure turbine on a variable cycle engine’s performance. One of the greatest challenges, during the design of a variable cycle engine is how to optimise the various cycles and then to match then to the capabilities of the engine components, the use of extensive variable geometry is required to achieve this. A method of matching variable cycle engines that was developed Cranfield University was adapted to cater for the use of a variable flow low pressure turbine. It was discovered that the implementation of variable geometry within the low pressure turbine could significantly reduce the requirements for variable geometry within the compressor system, at the cost of replacing well proven compressor variable geometry with high risk technology within the LP turbine. Utilising the variable flow turbine to expand the bypass ratio range of the engine was studied. Increasing the LPM bypass ratio to 1.1 and 1.2 yielded SFC reductions of 3% and 5% respectively, reducing the bypass ratio of the HPM to 0.1 gave a 20% increase in specific thrust. It was found that the performance benefits gained from expanding the bypass ratio are large enough to warrant further investigation into this concept.


2016 ◽  
Vol 0 (0) ◽  
Author(s):  
Wang Zhiqiang ◽  
Shen Xigang ◽  
Hu Jun ◽  
Gao Xiang ◽  
Liu Liping

AbstractA numerical method was developed to predict the aerodynamic stability of a high bypass ratio turbofan engine, at the landing stage of a large transport aircraft, when the thrust reverser was deployed. 3D CFD simulation and 2D aeroengine aerodynamic stability analysis code were performed in this work, the former is to achieve distortion coefficient for the analysis of engine stability. The 3D CFD simulation was divided into two steps, the single engine calculation and the integrated aircraft and engine calculation. Results of the CFD simulation show that with the decreasing of relative wind Mach number, the engine inlet will suffer more severe flow distortion. The total pressure and total temperature distortion coefficients at the inlet of the engines were obtained from the results of the numerical simulation. Then an aeroengine aerodynamic stability analysis program was used to quantitatively analyze the aerodynamic stability of the high bypass ratio turbofan engine. The results of the stability analysis show that the engine can work stably, when the reverser flow is re-ingested. But the anti-distortion ability of the booster is weaker than that of the fan and high pressure compressor. It is a weak link of engine stability.


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