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.

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.

scholarly journals FEASIBILITY OF BACKFIRE CONTROL AND PERFORMANCE USING CHANGES OF VALVE OVERLAP PERIOD FOR A HYDROGEN-FUELED ENGINE WITH EXTERNAL MIXTURE

2009 ◽  
Vol 12 (14) ◽  
pp. 77-85
Author(s):  
Cong Thanh Huynh ◽  
Kang Joon-Kyoung ◽  
Noh Ki-Cholo ◽  
Lee Jong-Tai ◽  
Mai Xuan Pham
Keyword(s):  
High Efficiency ◽  
Engine Performance ◽  
Continuous Variable ◽  
Variable Valve Timing ◽  
Valve Timing ◽  
Performance Loss ◽  
Wide Range ◽  
And Performance ◽  
Variable Valve ◽  
Valve Overlap

The development of a hydrogen-fueled engine using an external mixture (e.g., using port injection) with high efficiency and high power is dependent on the control of backfire. This work has developed a method to control backfire by reducing the valve overlap period. For this goal, a single-cylinder hydrogen-fueled research engine with a mechanical continuous variable valve timing (MCVVT) system was developed. This facility provides a wide range of valve overlap periods that can be continuously and independently varied during firing operation. In experiments, the behavior of backfire occurrence and engine performance are determined as functions of the valve overlap period for fuel-air equivalence ratios between 0.25 and 1.2. The results showed that the research engine with the MCVVT system has similar performance to a conventional engine, and is especially effective in controlling the valve overlap period. The obtained results demonstrate that decreasing the valve overlap period may be one of the methods for controlling backfire in a H engine. Also, a method for compensating performance loss due to shortened valve overlap period is recommended.

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.

Study on Design Criteria and Methods for the Valve Train of the Compressed-Air Engine

2013 ◽  
Vol 278-280 ◽  
pp. 159-164
Author(s):  
Zhao Zhang ◽  
Rui Bin Jia ◽  
Qi Hui Yu ◽  
Mao Lin Cai
Keyword(s):  
Valve Train ◽  
Compressed Air ◽  
Valve Lift ◽  
Design Criteria ◽  
Valve Timing ◽  
Wrap Angle ◽  
Cam Profile ◽  
Low Efficiency ◽  
And Performance ◽  
To Receive

The Compressed-air (CA) engine car is receiving increasingly worldwide attention because it takes advantages of renewable energy and has zero exhaust emissions. However it is limited by its low efficiency. This paper focuses on a systematic study on valve timing for optimizing its efficiency and performance. The requirements for the valve train were presented and an optimized polynomial cam profile was applied. Using the programme of Matlab, the influences of the half wrap angle and the maximum valve lift to the fullness coefficient were studied. The article proves that the designed cam profile should use the minimum maximum valve lift to receive the maximum fullness coefficient.

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.

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.

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.

Integrated Lifing Analysis Tool for Gas Turbine Components

2000 ◽  
Author(s):  
Tiedo Tinga ◽  
Wilfried P. J. Visser ◽  
Wim B. de Wolf ◽  
Michael J. Broomhead
Keyword(s):  
Gas Turbine ◽  
Mechanical Load ◽  
Engine Performance ◽  
Turbine Rotor ◽  
System Model ◽  
Analysis Tool ◽  
Turbine Rotor Blade ◽  
Turbine Component ◽  
Engine System ◽  
Life Consumption

A method to predict gas turbine component life based on analysis of engine performance is presented. Engine performance history is obtained from in-flight monitored engine parameters and flight conditions and downloaded for processing by a tool integrating a number of software tools and models. These subsequently include a comprehensive thermodynamical engine system model, heat transfer, thermal and mechanical load models, and finally, a life consumption model. Thermal and mechanical load distributions in the component as well as component life can be predicted. At this stage, the overall life prediction inaccuracy of the tool is dominated by the relatively high inaccuracy of the lifing model, and therefore, component life can only be predicted relative to a reference life. The tool is demonstrated with an analysis of the F100-PW-220 engine 3rd stage turbine rotor blade life consumption during a recorded RNLAF F-16 mission. Using the engine system model with a detailed control system, deterioration effects on engine performance were analyzed and the effect of engine deterioration on blade life consumption rate was determined. The tool has significant potential to enhance on-condition maintenance and optimize aircraft operational use.

Modeling an Energy Storage System Based on a Hybrid Renewable Energy System in Stand-alone Applications

2017 ◽  
Vol 68 (11) ◽  
pp. 2641-2645
Author(s):  
Alexandru Ciocan ◽  
Ovidiu Mihai Balan ◽  
Mihaela Ramona Buga ◽  
Tudor Prisecaru ◽  
Mohand Tazerout
Keyword(s):  
Renewable Energy ◽  
Energy Storage ◽  
Storage Systems ◽  
Renewable Energy Sources ◽  
Storage System ◽  
Energy Storage System ◽  
Compressed Air ◽  
Energy Sources ◽  
Energy Storage Systems ◽  
Hybrid Renewable Energy System

The current paper presents an energy storage system that stores the excessive energy, provided by a hybrid system of renewable energy sources, in the form of compressed air and thermal heat. Using energy storage systems together with renewable energy sources represents a major challenge that could ensure the transition to a viable economic future and a decarbonized economy. Thermodynamic calculations are conducted to investigate the performance of such systems by using Matlab simulation tools. The results indicate the values of primary and global efficiencies for various operating scenarios for the energy storage systems which use compressed air as medium storage, and shows that these could be very effective systems, proving the possibility to supply to the final user three types of energy: electricity, heat and cold function of his needs.

Renewable energy selection based on a new entropy and dissimilarity measure on an interval-valued neutrosophic set

2021 ◽  
pp. 1-18
Author(s):  
ShuoYan Chou ◽  
Truong ThiThuy Duong ◽  
Nguyen Xuan Thao
Keyword(s):  
Decision Making ◽  
Renewable Energy ◽  
Membership Function ◽  
Fossil Fuels ◽  
Multiple Criteria Decision Making ◽  
Clean Energy ◽  
Dissimilarity Measure ◽  
Neutrosophic Set ◽  
Trade Offs ◽  
And Performance

Energy plays a central part in economic development, yet alongside fossil fuels bring vast environmental impact. In recent years, renewable energy has gradually become a viable source for clean energy to alleviate and decouple with a negative connotation. Different types of renewable energy are not without trade-offs beyond costs and performance. Multiple-criteria decision-making (MCDM) has become one of the most prominent tools in making decisions with multiple conflicting criteria existing in many complex real-world problems. Information obtained for decision making may be ambiguous or uncertain. Neutrosophic is an extension of fuzzy set types with three membership functions: truth membership function, falsity membership function and indeterminacy membership function. It is a useful tool when dealing with uncertainty issues. Entropy measures the uncertainty of information under neutrosophic circumstances which can be used to identify the weights of criteria in MCDM model. Meanwhile, the dissimilarity measure is useful in dealing with the ranking of alternatives in term of distance. This article proposes to build a new entropy and dissimilarity measure as well as to construct a novel MCDM model based on them to improve the inclusiveness of the perspectives for decision making. In this paper, we also give out a case study of using this model through the process of a renewable energy selection scenario in Taiwan performed and assessed.

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