New Approach of Whole Engine Structural System Design

2014 ◽  
Author(s):  
Masaharu Andoh ◽  
Tatsuhito Honda ◽  
Kikuo Takamatsu
Keyword(s):  
Engine Performance ◽  
Design Approach ◽  
Jet Engines ◽  
Structural System ◽  
New Approach ◽  
Jet Engine ◽  
Conventional Design ◽  
Engine Design ◽  
Current Design ◽  
And Performance

Fuel-efficient jet engines are developed by many companies. In the conventional design approach of a jet engine, many parameters are investigated independently. Consequently, a developed jet engine by this approach meets conventional design criteria but there is still room for improvement of engine performance. In this research, the new design approach of a jet engine that integrates these design objectives is developed and performance of a jet engine is evaluated. The goal is to develop the design approach of a fuel-efficient and robust jet engine. In current design, a jet engine is developed with a focus on not only performance improvement but also robustness. Therefore, Taguchi method is adopted in order to assess robustness. By this method, a jet engine is optimized based on the analysis that minimizes deterioration and variation of SFC. As a result, more efficient engine design is realized with the new design approach that directly deals with SFC.

Correlations of Soot Formation in Turbojet Engines and in Laboratory Flames

1984 ◽  
Author(s):  
R. J. Gill ◽  
D. B. Olson ◽  
H. F. Calcote
Keyword(s):  
Soot Formation ◽  
Dominant Role ◽  
Engine Performance ◽  
Smoke Point ◽  
Jet Engines ◽  
Fuel Property ◽  
Jet Engine ◽  
Related Data ◽  
Polycyclic Aromatic ◽  
Engine Testing

Smoke related performance of both jet engine and research combustors has been correlated with several fuel properties. The smoke related data included: smoke number, liner temperature rise, and radiation flux to the combustor wall; fuel parameters included: percent hydrogen, percent aromatic, percent polycyclic aromatic, smoke point, and the threshold soot index, TSI. The research combustor results correlated best with the threshold sooting index. While some correlations with engine performance were excellent, no single fuel property was generally useful in evaluating smoke related performance, mainly because of insufficient data on the fuels tested in the jet engine programs, e.g., percent aromatics specifies a class of fuels which span > 50% of the possible range of sooting tendencies. It is, however, demonstrated that fuel composition plays a dominant role in determining smoke related engine parameters. It is recommended that fuels used for engine testing programs be chemically analyzed in greater detail or be made available for laboratory measurements of soot thresholds and soot yields until a sufficient data base is available to establish a laboratory technique of predicting relative smoke related performance of fuels in jet engines.

Computational Analysis in Test Cell Design With Application in Emissions Control

2014 ◽  
Author(s):  
Paul Lee ◽  
Ligong Yang ◽  
Caner Demirdogen
Keyword(s):  
Performance Test ◽  
Combustion Engine ◽  
Engine Performance ◽  
Test Cell ◽  
Cell Design ◽  
Engine Design ◽  
Computational Fluid Dynamics Cfd ◽  
Test Cells ◽  
And Performance ◽  
Conversion Efficiencies

Computer-Aided Engineering (CAE) tools have been widely used in the design of automotive components and systems. Methods, procedures and measurables for analyses involving Internal Combustion Engine (ICE) components are well-defined and well developed. Comparatively, significantly less attention has been paid to the design and analysis of test cells. Better designed test cells will lead to increased test cell availability and thus also increases engine performance test opportunities. This trend was observed in Cummins Inc. where CAE-guided test cell designs improved test-cell availability and rate of engine development. Here, improved conversion efficiencies in test cell Selective Catalyst Reduction (SCR) modules were predicted using Computational Fluid Dynamics (CFD) tools, and validated against data collected from the test cells. The resultant improvements resulted in dramatic increases in test cell up-time. This paper documents how CAE tools commonly used in engine design were successfully expanded to aid the design of Cummins Inc. test cells. It presents the CFD methods that were used in this analysis, compares CFD predictions to actual conversion efficiencies in the SCR module, and also proposes a set of analysis tasks and methods that can be applied to improve test cell design and performance in the future.

Model Based Control Concepts for Jet Engines

2001 ◽  
Author(s):  
Klaus Lietzau ◽  
Andreas Kreiner
Keyword(s):  
Turbine Blades ◽  
Engine Performance ◽  
Current Control ◽  
Engine Control ◽  
Jet Engines ◽  
Jet Engine ◽  
Engine Model ◽  
Model Based ◽  
Safety Margins ◽  
Engine Life

Many jet engine variables cannot be measured in-flight or can only be measured with a complex, and hence unreliable, instrumentation system. This includes variables that are of imminent importance for the safe operation of the engine or for engine life, such as the temperature of the high pressure turbine blades or the surge margins of the turbo compressors, for instance. Current control systems therefore transform limits on these variables into limits on other variables measured by the engine’s sensors. This leads to increased safety margins and thus to non-optimal engine performance. An onboard engine model incorporated into the engine control system could provide information about all engine variables. This could enable further control and monitoring system optimisations leading to improved engine performance, reduced fuel consumption, increased safety and engine life. This paper explains the principle of model based engine control and gives an overview about possible applications for conventional and also thrust vectored jet engines. Modeling methods for real-time simulation as well as methods for online model adaptation are presented. The potential of model based jet engine control is analyzed and fortified by some prototype realizations.

Direct Integration of Axial Turbomachinery Preliminary Aerodynamic Design Calculations in Engine Performance Component Models

2018 ◽  
Author(s):  
Ioannis Kolias ◽  
Alexios Alexiou ◽  
Nikolaos Aretakis ◽  
Konstantinos Mathioudakis
Keyword(s):  
Axial Flow ◽  
Engine Performance ◽  
Single Step ◽  
Design Calculation ◽  
Aerodynamic Design ◽  
Performance Modelling ◽  
Engine Design ◽  
And Performance ◽  
Design Calculations ◽  
Component Models

In the context of an engine design calculation, isentropic or polytropic efficiencies of turbomachinery components are assumed at the outset of the cycle analysis and their values are updated or validated following the aerodynamic design of the components. In the present paper, aerodynamic design calculations of axial-flow compressors and turbines are directly integrated into the corresponding performance component models. This creates a consistent, single-step preliminary design and performance modelling process using a relatively small number of physical and geometric inputs. The aerodynamic design for establishing a component’s overall efficiency is accomplished through a mean-line, stage-by-stage approach where the stagewise isentropic efficiency is calculated employing either loss or semi-empirical correlations. From this process, the stagewise flow annulus radii are also obtained and are used to axially size the component stages assuming the blade aspect ratio and axial gapping distributions. The component flowpath geometry is then produced by simply “stacking” axially the component stages. The developed method is validated against publicly available data for a high-pressure compressor and a low-pressure turbine. Finally, the effectiveness of the method is demonstrated by considering the multi-point design of a High Bypass Ratio Geared Turbofan Engine with bypass Variable Area Nozzle.

Deterioration Detection and Health Monitoring in Aircraft Jet Engines

2012 ◽  
Author(s):  
N. Daroogheh ◽  
A. Baniamerian ◽  
H. Nayyeri ◽  
K. Khorasani
Keyword(s):  
Performance Analysis ◽  
Statistical Method ◽  
Health Monitoring ◽  
Engine Performance ◽  
Jet Engines ◽  
Differential Analysis ◽  
Analysis Method ◽  
Jet Engine ◽  
Engine Model ◽  
Cumulative Sum Method

In this paper the problem of jet engine deterioration detection and health monitoring is investigated by utilizing two methods. The first method is based on the fusion of the modified CUSUM (CUmulative SUM) method with the differential analysis approach. An enhanced differential analysis method is developed through which the degradation is captured from the unsymmetrical performance analysis of both engines on an aircraft. This is achieved by considering the effects of minor maintenance actions that are not reported. In the second approach, a statistical method based on the Hotelling’s T2-test approach is utilized to detect gradual degradations in the engine performance. The performance of our proposed approaches is evaluated by implementing them on a dual spool engine model that is developed by using the GSP software.

Numerical Simulation of Valve Timing and Size on a Compressed Air Engine Performance

2011 ◽  
Vol 130-134 ◽  
pp. 781-785
Author(s):  
Ye Jian Qian ◽  
Cheng Ji Zuo ◽  
Zhi Fang Chen ◽  
Hong Ming Xu ◽  
Miroslaw L. Wyszynski
Keyword(s):  
Numerical Simulation ◽  
Renewable Energy ◽  
Engine Performance ◽  
Compressed Air ◽  
System Model ◽  
Valve Timing ◽  
Engine Design ◽  
Engine System ◽  
Critical Requirement ◽  
And Performance

The compressed air engine is receiving increasingly worldwide attention because it takes advantage of renewable energy and has zero exhaust emissions. This paper presents a systematic study on valve timing and size of a prototype compressed air engine for optimizing its efficiency and performance. An in-house air engine system model has been developed using the FLOWMASTER platform. The simulated results show that the optimizing valve timings is probably the most critical requirement in the compressed air engine design process.

Risk Monitoring During Design and Development of Aircraft Engines Using Monte Carlo Simulations and Performance Model

2009 ◽  
Author(s):  
Hassan Abdullahi ◽  
Klaus-Juergen Schmidt
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
New Technologies ◽  
Engine Performance ◽  
Performance Model ◽  
Design And Development ◽  
Risk Monitoring ◽  
Engine Design ◽  
And Performance ◽  
Time Frames

The process of engine design and development is very complex since it comprises various disciplines with their own sub-processes. In addition, the requirements the new generation of engines has to meet become more and more ambitious, which calls for the employment of new technologies. But this involves a very high risk with regard to fulfilling specification requirements, and also with regard to adherence to budgets as well as time frames. In this paper, an approach of risk monitoring during the engine design and development phase is presented. The approach uses Monte-Carlo simulations, which are based on an engine performance synthesis model. For the purpose, a helicopter engine is used as an example for demonstration of the method.

Use of Computer Simulation Techniques to Assess Thrust Rating as a Means of Reducing Turbo-Jet Life Cycle Costs

1994 ◽  
Author(s):  
B. Devereux ◽  
R. Singh
Keyword(s):  
Computer Simulation ◽  
Life Cycle ◽  
High Performance ◽  
Engine Performance ◽  
Simulation Technique ◽  
Life Cycle Costs ◽  
Clear Understanding ◽  
Jet Engines ◽  
Jet Engine ◽  
Baseline Values

This paper investigates the concept of thrust rating as a means towards reducing the life cycle costs of turbo-jet engine ownership. Towards this end, the concepts of life usage and thrust rating will be discussed to provide a clear understanding of the goals and methods involved in this investigation. In general, all “serviceable” engines will experience varying levels of performance above baseline values. Thrust rating ideally seeks to limit engine performance to baseline values, thereby converting performance into life. In particular, this paper will present a general computer simulation technique that may be applied to any turbo-jet engine to quantify the life cycle savings resulting from the adoption of thrust rating techniques. The inter-relationships that exist between thrust rating and many practical in-service aspects of turbo-jet usage including performance degradation, operational roles and maintenance practices and policies will be investigated. Some strengths and limitations of the simulation technique will also be identified. This paper will discuss general guidelines for investigating the feasibility of performing thrust rating on various turbo-jet engines. While this technique is likely to be of greatest interest to users of high performance military turbo-jet engines, its principles can be adapted for other gas turbine uses.

Development of an improved design methodology and front steering design guideline for small-wheel bicycles for better stability and performance

2020 ◽  
Vol 234 (3) ◽  
pp. 227-244
Author(s):  
Milan Paudel ◽  
Fook Fah Yap
Keyword(s):  
Design Methodology ◽  
Design Guidelines ◽  
Design Approach ◽  
Design Parameters ◽  
Design Practice ◽  
Frame Design ◽  
Current Design ◽  
And Performance ◽  
Improved Design ◽  
Bicycle Design

The maneuverability and compactness of small-wheel and folding bicycles are greatly appreciated. Nonetheless, the performance of these small-wheel bicycles as compared to the big-wheel bicycles has always been questioned. They are often blamed for being less stable, wobbly, or twitchy. It is still unclear how the performance of the small-wheel bicycle designs can be improved. Both small- and big-wheel bicycles are designed with similar ergonomics; therefore, the focus has been on the front steering design. The steering design parameters of 91 big-wheel and 27 small-wheel bicycles were compared, bearing in mind the available front steering design guidelines to understand: (1) the influence of big-wheel bicycle’s frame design on small-wheel bicycles and (2) most common range of design parameters used in current bicycle designs. The analysis showed a strong influence of current big-wheel bicycle design practice on front frame parameter selection of small-wheel bicycles. Furthermore, the self-stability comparison over the most common design range confirmed the lesser stability in the current small-wheel bicycle designs at normal riding speed. However, it was also found that the lesser stability was not the result of small wheels per se, but rather owing to an inadequacy in the current design approach to addressing the complex influence of reducing wheel size and bicycle frame design on its stability and performance. Therefore, an improved design methodology was adopted by incorporating the bicycle dynamics into the current design approach and the front steering design guidelines for small-wheel bicycles have been developed. The guidelines contradict the current small-wheel bicycle design practice, as they recommend steeper headtube angles for small-wheel bicycles. The guidelines were validated with good agreement between the theoretical and experimental results on two prototype 20-inch-wheel bicycles having counter-intuitive steering geometry.

Generation of Physically Based Analysis Factors to Improve Synthesis Models of Jet Engines

2005 ◽  
Author(s):  
Xavier Canalias ◽  
Frank Ko¨pf ◽  
Peter Sahm
Keyword(s):  
Engine Performance ◽  
Good Choice ◽  
Jet Engines ◽  
Analysis Method ◽  
Jet Engine ◽  
Analysis By Synthesis ◽  
Physically Based ◽  
The Common ◽  
Set Up ◽  
Definition Of

The ANalysis by SYNthesis (ANSYN) technique is a standard performance analysis method widely used in industry. It is currently used to evaluate engine performance from tests and to derive correcting factors (i.e. ANSYN factors) that modify certain parameters of the components’ characteristics in order to allow the reproduction of real engine behaviour by means of a synthesis calculation. Once they have been determined, these ANSYN factors can be implemented into the common synthesis tools to accurately predict the behaviour of the engine in non-tested conditions. The definition of how the engine synthesis will be modified to reproduce the measured cycle is called the “matching scheme”. It is the choice of the parameters that will not be modified, the ones that will be scaled and the ones that will be used as a reference. A good choice of the ANSYN factors and of the magnitudes used to tabulate them will make possible their physical interpretation and analysis, which can lead to the identification of inaccurate assumptions and phenomena that had not been accurately taken into account in the previous performance models. This understanding of their origin is a prerequisite for any improvement of the models and could lead to an enhanced process for the development of non-dimensional jet engine characteristics. In this study, a matching scheme for the RR-BR710 engine has been set up, implemented and applied. This method is an alternative to some of the currently used in the Rolls-Royce Deutschland ANSYN tools. The main goal of the present work has been the definition of a matching scheme that leads to the obtention of physically meaningful ANSYN factors. This allows their subsequent analysis and interpretation and can provide useful information on engine component operation and on the phenomena responsible for the observed deviations from predicted engine behaviour.

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