Probabilistic Analysis of a Turbofan Secondary Flow System

2004 ◽  
Author(s):  
David Cloud ◽  
Ethan Stearns
Keyword(s):  
Secondary Flow ◽  
Probabilistic Analysis ◽  
Flow System ◽  
Engine Performance ◽  
Root Cause ◽  
Engine Design ◽  
Bearing Loads ◽  
Input Variables ◽  
Time Required ◽  
Individual Input

This paper documents a probabilistic analysis of the secondary flow system in a modern commercial turbofan engine. The purpose of this analysis is to investigate the variability in the high and low rotor bearing loads and total secondary flow due to the inherent uncertainty in manufacturing processes and engine performance. In addition to quantifying the variability in bearing load and secondary flow, the sensitivity of the parameters to individual input variables is determined. The system was found to behave linearly, resulting in negligible mean shifts due to input variation. The importance of correlation among the performance parameters will be addressed, as well as the effects of different correlations. Methods used to reduce the time required for the analysis will also be discussed. This type of analysis has many applications in cost reduction, engine design, optimization, and root cause analysis that will be covered in this paper.

Influence of secondary flow on aero-engine performance

2013 ◽  
Author(s):  
Xiao-bo Zhang ◽  
Zhan-xue Wang ◽  
Zeng-wen Liu
Keyword(s):  
Secondary Flow ◽  
Engine Performance ◽  
Aero Engine

Analysis and Reduction of the Waste in the Work Process Using Time Study Analysis: A Case Study

2014 ◽  
Vol 660 ◽  
pp. 971-975 ◽  
Author(s):  
Mohd Norzaim bin Che Ani ◽  
Siti Aisyah Binti Abdul Hamid
Keyword(s):  
Cycle Time ◽  
Lean Manufacturing ◽  
Value Added ◽  
Time Study ◽  
Study Approach ◽  
Root Cause ◽  
Wide Range ◽  
Unit Of Work ◽  
Time Required ◽  
The Impact

Time study is the process of observation which concerned with the determination of the amount of time required to perform a unit of work involves of internal, external and machine time elements. Originally, time study was first starting to be used in Europe since 1760s in manufacturing fields. It is the flexible technique in lean manufacturing and suitable for a wide range of situations. Time study approach that enable of reducing or minimizing ‘non-value added activities’ in the process cycle time which contribute to bottleneck time. The impact on improving process cycle time for organization that it was increasing the productivity and reduce cost. This project paper focusing on time study at selected processes with bottleneck time and identify the possible root cause which was contribute to high time required to perform a unit of work.

scholarly journals Effective Reduction in Utility Cost in A Beverage Plant

2019 ◽  
Vol 8 (6S3) ◽  
pp. 2108-2112
Keyword(s):  
Power Analysis ◽  
Cooling Tower ◽  
Quality Cost ◽  
Value Stream ◽  
Root Cause ◽  
A Value ◽  
Effective Reduction ◽  
Input Variables ◽  
Utility Cost ◽  
Value Stream Map

This project. is about in-depth focus on equipment power analysis and effective reduction in Utility and Quality Cost. A Value Stream Map has been developed and analyzed to identify critical focus areas in Utilities, Process and Line. The most significant key input variables have been identified and those are Boiler, Old-Utilities, New-Utilities, Process Area & Cooling Towers, which are prioritized based upon their relationship with the key output metric. Key input, process, and output metrics have been identified. As a part of Root cause analysis, Power consumption is high due to Running of 2 compressors, yolk chiller, raw water pump, cooling tower pumps & fan and new refrigeration for cooling tower pump. Potential implementation solutions are to be developed, evaluated, and optimized based upon their effectiveness impacting the key output, robustness to variation and ease of implementation. The final improvement solution has been incorporated into the process organization and the improvement gains of 3 – 25 KWH are being expected.

Model Based Design and Optimization for Large Bore Engines: Some Industrial Case Studies

2017 ◽  
Author(s):  
Prashant Srinivasan ◽  
Sanketh Bhat ◽  
Manthram Sivasubramaniam ◽  
Ravi Methekar ◽  
Maruthi Devarakonda ◽  
...  
Keyword(s):  
System Design ◽  
Case Studies ◽  
Control Strategy ◽  
Internal Combustion Engines ◽  
Cost Optimization ◽  
Engine Performance ◽  
Design And Optimization ◽  
Model Based ◽  
Performance Requirements ◽  
Engine Design

Large bore reciprocating internal combustion engines are used in a wide variety of applications such as power generation, transportation, gas compression, mechanical drives, and mining. Each application has its own unique requirements that influence the engine design & control strategy. The system architecture & control strategy play a key role in meeting the requirements. Traditionally, control design has come in at a later stage of the development process, when the system design is almost frozen. Furthermore, transient performance requirements have not always been considered adequately at early design stages for large engines, thus limiting achievable controller performance. With rapid advances in engine modeling capability, it has now become possible to accurately simulate engine behavior in steady-states and transients. In this paper, we propose an integrated model-based approach to system design & control of reciprocating engines and outline ideas, processes and real-world case studies for the same. Key benefits of this approach include optimized engine performance in terms of efficiency, transient response, emissions, system and cost optimization, tools to evaluate various concepts before engine build thus leading to significant reduction in development time & cost.

Field-Proven Well Surveillance Techniques Designed for an Early Well Scaling Diagnosis and Timely Well Performance Reinstatement: Case Study from the Kashagan Field

2021 ◽  
Author(s):  
Aktoty Kauzhanova ◽  
Lyudmila Te ◽  
John Reedy ◽  
Thaddeus Ivbade Ehighebolo ◽  
Mirko Bastiaan Heinerth ◽  
...  
Keyword(s):  
Surveillance Program ◽  
Successful Implementation ◽  
Well Testing ◽  
Well Performance ◽  
Root Cause ◽  
Operating Environments ◽  
Initial Stage ◽  
Calcite Deposition ◽  
Time Required

Abstract Some wells in the Kashagan field did not perform as well as expected. Despite producing virtually no water, calcite deposition was found to be the root cause of the problem. A comprehensive well surveillance program, which was proven to be very efficient for an early scaling diagnosis, was developed by the operator, North Caspian Operating Company (hereafter NCOC). As a result, well scaling is currently well managed and prevented from reoccurring. The objective of this paper is to share an early experience with well scaling in the Kashagan field, as well as to describe the developed set of well surveillance techniques. The aim of the various well surveillance techniques discussed in this paper is to improve an Operator's ability to identify the very first signs of scale accumulation. This, in its turn, enables to introduce timely adjustments to the well operating envelope and to schedule a scale remediation / inhibition treatment with the intention to prevent any potential scaling initiation from further development. The approach is quite extensive and incorporates continuous BHP/BHT monitoring, routine well testing, PTA analysis, and fluid/water sampling. Developed approach experienced multiple revisions and modifications. Further optimization continues, however, the described well surveillance techniques represent the latest Operator's vision on the most efficient way for well scaling monitoring and identification. In the Kashagan field, BHP/BHT readings have proved to be the most direct and instantaneous indication of any early signs of potential deterioration in well performance (qualitative analysis) while well testing and PTAs are considered as the most essential techniques in confirming and quantifying scaling severity (quantitative analysis). It is important to mention that BHT increase is explained by Joule-Thomson heating effect being specific for the Kashagan fluid (happening during increased pressure drawdown). This, in turns, enables to predict future well performance, design well operating envelop accordingly and, most importantly, develop a yearly schedule for proactive well treatments with SI. In conclusion, it shall be highlighted that discussed complex of well surveillance techniques has been concluded to be very efficient and reliable tool in identifying any scaling tendencies at its initial stage. Due to successful implementation of this approach in the Kashagan field, scale development is now well-managed and kept under control. To mention, that utilization of well surveillance techniques and methods outlined in this paper may reduce the time required to identify and ultimately mitigate well scale accumulation in any active assets with similar operating environments.

Paper 4: The Effect of Combustion Chamber Shape and Other Engine Design Factors on Exhaust Emissions

1968 ◽  
Vol 183 (5) ◽  
pp. 133-144 ◽  
Author(s):  
P. L. Dartnell ◽  
C. L. Goodacre ◽  
P. V. Lamarque
Keyword(s):  
Combustion Chamber ◽  
Engine Performance ◽  
Exhaust System ◽  
Exhaust Emissions ◽  
Intake Manifold ◽  
Valve Timing ◽  
Mixture Formation ◽  
Engine Design ◽  
Basic Engine ◽  
Design Factors

A Heron combustion chamber engine of 2 litre capacity has been utilized to investigate the effect of combustion chamber shape, increased mixture movement, valve timing, mixture formation, and reaction in the exhaust system on engine performance and level of exhaust emissions using the seven-mode U.S. Federal cycle. Such factors as carburettor weakening and limitation of intake manifold vacuum during overrun have been included in this investigation, and it has been shown that it is possible to reduce exhaust emissions and also satisfy the current U.S. requirements with an engine giving acceptable performance, improved economy, and unaffected reliability. Much of the information reported may be negative in terms of improvement to exhaust emissions by detailed engine design. Nevertheless, some positive conclusions have been reached as a result of this work, and it is hoped that this will draw forth more informed discussion than the authors have been able to assemble from the work attempted with one basic engine.

Engine Calibration Optimization Based on its Surrogate Models

2019 ◽  
Author(s):  
Anuj Pal ◽  
Yan Wang ◽  
Ling Zhu ◽  
Guoming G. Zhu
Keyword(s):  
Computational Cost ◽  
Engine Performance ◽  
Expected Improvement ◽  
Boost Pressure ◽  
Control Parameters ◽  
Variable Geometry Turbocharger ◽  
Engine Calibration ◽  
Pareto Optimal Set ◽  
Time Required ◽  
Kriging Metamodeling

Abstract Diesel engines are becoming increasingly complex to control and calibrate with the desire of improving fuel economy and reducing emissions (NOx and Soot) due to global warming and energy usage. With ever increased control features, it is becoming more and more difficult to calibrate engine control parameters using the traditional engine mapping based methods due to unreasonable calibration time required. Therefore, this research focuses on the problem of performing engine calibration within a limited budget by efficiently optimizing three control parameters: namely variable geometry turbocharger (VGT) position, exhaust gas recirculation (EGR) valve position, and start of injection (SOI). Engine performance in terms of fuel consumption (BSFC) and emissions (NOX) are considered as objective function here with the constraint on boost pressure and engine load (BMEP). Since the engine calibration process requires a large number of high-fidelity evaluations, surrogate modeling methods are used to perform calibration quickly with a significantly reduced computational budget. Kriging metamodeling is used for this work with Expected Improvement (EI) as acquisition function. Results show more than 60% decrease in computational cost with results close to actual near Pareto optimal set.

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.

The Significance of Laboratory Octane Numbers in Relation to Road Anti-knock Performance

1951 ◽  
Vol 5 (1) ◽  
pp. 111-140
Author(s):  
H. J. Eatwell ◽  
J. G. Withers
Keyword(s):  
United States Of America ◽  
Research Method ◽  
Engine Performance ◽  
The United States ◽  
Fuel Composition ◽  
The Road ◽  
High Severity ◽  
Engine Design ◽  
Motor Fuels ◽  
Lower Severity

Fuel composition plays a prominent part in deciding the compression ratio to be adopted for an engine, since composition directly affects the knocking tendencies of motor fuels, and knock in turn imposes a limitation on engine performance. The engine conditions which affect knock are discussed and the fact that all fuels do not react equally to these conditions is dealt with in some detail. Laboratory and road knock rating methods are described, and results of tests on a number of fuels and cars, both in Great Britain and in the United States of America are used to demonstrate a relationship between laboratory and road antiknock ratings. It is shown that the road anti-knock performance of fuels is directly affected by their “sensitivity”, to a greater or lesser degree depending on engine “severity”. Severe engines are at a disadvantage in not being able to make full use of the high Research Method Ratings of sensitive fuels, and the factors in engine design and operation which cause high severity are discussed. It is emphasized how necessary it is to produce designs of engines of lower “severity”.

LPG/Gasoline Dual-Fuel Engine Design and Investigation about its Performance

2013 ◽  
Vol 333-335 ◽  
pp. 2025-2029
Author(s):  
Wei Liu ◽  
Sheng Ji Liu ◽  
Xin Kuang ◽  
Jian Sun
Keyword(s):  
Performance Test ◽  
Process Analysis ◽  
Combustion Process ◽  
Engine Performance ◽  
Dual Fuel ◽  
Pressure Curve ◽  
Engine Design ◽  
Crank Angle ◽  
The Us ◽  
Us Epa

In order to burning LPG and gasoline and dual fueled (LPG and gasoline) in the same engine, a new multi-function engine was refitted and designed based on 188F gasoline, mutative effects on the power and emission performance when burning those three kind fuel were investigated by the engine operated with the US EPA Phase-Ⅱ. Three schemes for the carburetor throat were designed. Balanced of the power and economy performance, when the diameter of the carburetor throat is 23mm, the performance was the best. By carrying engine performance test and the combustion process analysis, the results showed that: when the throttle was full opened, the power of burning only gasoline was 7.97kW, 0.5 kW and 0.28kW higher than burning LPG and dual –fuel. Burning gasoline pressure curve with the crank Angle siege area is the largest. As the emission test shows, when separately burning LPG and gasoline and dual fueled, the tendency of the excess air coefficient and the emission characteristics with the load change are same. When using LPG and dual-fuel, compared with burning gasoline, HC and NOx emission were reduced.

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