Design and Validation of a Reduced Test Matrix for the Autoignition of Gas Turbine Fuel Blends

2005 ◽  
Author(s):  
Jaap de Vries ◽  
Eric L. Petersen
Keyword(s):  
Design Methodology ◽  
Fuel Composition ◽  
Fuel Blend ◽  
Reasonable Time ◽  
Test Matrix ◽  
Fuel Blends ◽  
Wide Range ◽  
Aero Engine ◽  
Burner Design ◽  
And Performance

Changes in fuel composition for both aero-engine as well as power generation applications is a topic of concern since fuel variability can have a great impact on the reliability and performance of the burner design. Autoignition experiments for a wide range of likely fuel blends containing CH4 mixed with combinations of C2H6, C3H8, C4H10, C5H12, and H2 are planned in the authors’ shock-tube laboratory. However, testing every possible fuel blend and interaction is not feasible within a reasonable time and cost. To predict the surface response over the complete mixture domain, a special experimental design has been developed reducing the amount of ‘trials’ needed significantly from 243 to only 41 using the Box-Behnkin factorial design methodology. Kinetics modeling was used to obtain numerical results for this matrix of fuel blends when applied to autoignition at a temperature of 800 K and pressure of 17 atm. A further attempt was made to reduce the 41-test matrix to a 21-test matrix. This was done using special mixture experimental techniques, and the kinetics model was used to compare the smaller matrix to the expected results of the larger one. The new 21-Test matrix produced a numerical correlation that agreed well with the results from the 41-test matrix, indicating that the smaller matrix will provide the same autoignition information as the larger one with acceptable precision.

scholarly journals Influence of Combustion Characteristics and Fuel Composition on Exhaust PAHs in a Compression Ignition Engine

Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2575 ◽  
Author(s):  
Hamisu Adamu Dandajeh ◽  
Midhat Talibi ◽  
Nicos Ladommatos ◽  
Paul Hellier
Keyword(s):  
Environmental Protection Agency ◽  
Ignition Delay ◽  
Combustion Characteristics ◽  
Exhaust Emission ◽  
Fuel Composition ◽  
Particulate Phase ◽  
Compression Ignition Engine ◽  
Fuel Blend ◽  
Fuel Blends ◽  
Methyl Decanoate

This paper reports an experimental investigation into the effects of fuel composition on the exhaust emission of toxic polycyclic aromatic hydrocarbons (PAHs) from a diesel engine, operated at both constant fuel injection and constant fuel ignition modes. The paper quantifies the US EPA (United State Environmental Protection Agency) 16 priority PAHs produced from combustion of fossil diesel fuel and several model fuel blends of n-heptane, toluene and methyl decanoate in a single-cylinder diesel research engine based on a commercial light duty automotive engine. It was found that the level of total PAHs emitted by the various fuel blends decreased with increasing fuel ignition delay and premixed burn fraction, however, where the ignition delay of a fuel blend was decreased with use of an ignition improving additive the level of particulate phase PAH also decreased. Increasing the level of toluene present in the fuel blends decreased levels of low toxicity of two to four ring PAH, while displacing n-heptane with methyl decanoate increased particulate phase adsorbed PAH. Overall, the composition of the fuels investigated was found to have more influence on the concentration of exhaust PAHs formed than that of combustion characteristics, including ignition delay, peak heat release rate and the extent of the premixed burn fractions.

City destinations, overtourism and governance

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Harold Goodwin
Keyword(s):  
Design Methodology ◽  
Empirical Studies ◽  
Content Type ◽  
Large Numbers ◽  
Wide Range ◽  
Conflicting Interests ◽  
And Performance ◽  
National Governments

Purpose There has been limited research on the governance of cities coping with large numbers of tourists. Empirical studies of the ways in which elected authorities in cities balance the conflicting interests of the tourism stakeholders, other businesses, communities and residents. It is clear that this requires a whole of government approach, and cities generally have a wide range of expertise and powers. Design/methodology/approach This paper uses conceptual viewpoint approach. Findings As the cases of Barcelona and Venice demonstrate, they are unable to manage the flows of day visitors arriving from the surrounding region, and the airports, ports, roads and railways are managed by regional and national governments. The different functions, powers and performance of government bodies need to be researched if we are to secure a better understanding of the complex and multi-layered activity of tourism can best be governed. Originality/value This is an original viewpoint.

scholarly journals Research on the Combustion, Energy and Emission Parameters of Various Concentration Blends of Hydrotreated Vegetable Oil Biofuel and Diesel Fuel in a Compression-Ignition Engine

Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2978 ◽  
Author(s):  
Alfredas Rimkus ◽  
Justas Žaglinskis ◽  
Saulius Stravinskas ◽  
Paulius Rapalis ◽  
Jonas Matijošius ◽  
...  
Keyword(s):  
Fuel Consumption ◽  
Vegetable Oil ◽  
Diesel Fuel ◽  
Direct Injection ◽  
Engine Performance ◽  
Compression Ignition Engine ◽  
Fuel Blend ◽  
Fuel Blends ◽  
Wide Range ◽  
Torque Load

This article presents our research results on the physical-chemical and direct injection diesel engine performance parameters when fueled by pure diesel fuel and retail hydrotreated vegetable oil (HVO). This fuel is called NexBTL by NESTE, and this renewable fuel blends with a diesel fuel known as Pro Diesel. A wide range of pure diesel fuel and NexBTL100 blends have been tested and analyzed: pure diesel fuel, pure NexBTL, NexBTL10, NexBTL20, NexBTL30, NexBTL40, NexBTL50, NexBTL70 and NexBTL85. The energy, pollution and in-cylinder parameters were analyzed under medium engine speed (n = 2000 and n = 2500 rpm) and brake torque load regimes (30–120 Nm). AVL BOOST software was used to analyze the heat release characteristics. The analysis of brake specific fuel consumption showed controversial results due to the lower density of NexBTL. The mass fuel consumption decreased by up to 4%, and the volumetric consumption increased by up to approximately 6%. At the same time, the brake thermal efficiency mainly increased by approximately 0.5–1.4%. CO, CO2, NOx, HC and SM were analyzed, and the change in CO was negligible when increasing NexBTL in the fuel blend. Higher SM reduction was achieved while increasing the percentage of NexBTL in the blends.

Analysis of organic removal rates in the aerated submerged fixed film process

1998 ◽  
Vol 38 (8-9) ◽  
pp. 213-221 ◽  
Author(s):  
Mohamed F. Hamoda ◽  
Ibrahim A. Al-Ghusain
Keyword(s):  
Pilot Plant ◽  
Removal Rate ◽  
Domestic Wastewater ◽  
Removal Rates ◽  
Hydraulic Loading ◽  
Organic Removal ◽  
Wide Range ◽  
Fixed Film ◽  
Cod Removal Rate ◽  
And Performance

Performance data from a pilot-plant employing the four-stage aerated submerged fixed film (ASFF) process treating domestic wastewater were analyzed to examine the organic removal rates. The process has shown high BOD removal efficiencies (> 90%) over a wide range of hydraulic loading rates (0.04 to 0.68 m3/m2·d). It could also cope with high hydraulic and organic loadings with minimal loss in efficiency due to the large amount of immobilized biomass attained. The organic (BOD and COD) removal rate was influenced by the hydraulic loadings applied, but organic removal rates of up to 104 kg BOD/ m2·d were obtained at a hydraulic loading rate of 0.68 m3/m2·d. A Semi-empirical model for the bio-oxidation of organics in the ASFF process has been formulated and rate constants were calculated based on statistical analysis of pilot-plant data. The relationships obtained are very useful for analyzing the design and performance of the ASFF process and a variety of attached growth processes.

scholarly journals Fabrication and Compressive Behavior of a Micro-Lattice Composite by High Resolution DLP Stereolithography

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 785
Author(s):  
Chow Shing Shin ◽  
Yu Chia Chang
Keyword(s):  
High Resolution ◽  
Lattice Structure ◽  
Low Cost ◽  
Hierarchical Structures ◽  
Dip Coating ◽  
Unit Cell ◽  
Digital Light Processing ◽  
Unit Cell Size ◽  
Wide Range ◽  
And Performance

Lattice structures are superior to stochastic foams in mechanical properties and are finding increasing applications. Their properties can be tailored in a wide range through adjusting the design and dimensions of the unit cell, changing the constituent materials as well as forming into hierarchical structures. In order to achieve more levels of hierarchy, the dimensions of the fundamental lattice have to be small enough. Although lattice size of several microns can be fabricated using the two-photon polymerization technique, sophisticated and costly equipment is required. To balance cost and performance, a low-cost high resolution micro-stereolithographic system has been developed in this work based on a commercial digital light processing (DLP) projector. Unit cell lengths as small as 100 μm have been successfully fabricated. Decreasing the unit cell size from 150 to 100 μm increased the compressive stiffness by 26%. Different pretreatments to facilitate the electroless plating of nickel on the lattice structure have been attempted. A pretreatment of dip coating in a graphene suspension is the most successful and increased the strength and stiffness by 5.3 and 3.6 times, respectively. Even a very light and incomplete nickel plating in the interior has increase the structural stiffness and strength by more than twofold.

BSAS Ethical Policy British Society of Animal Science Ethical guidelines for research in animal science

2005 ◽  
Vol 2005 ◽  
pp. 247-253 ◽  
Author(s):  
S. Jarvis ◽  
J.E.L. Day ◽  
B. Reed
Keyword(s):  
Ethical Issues ◽  
Science Research ◽  
British Society ◽  
Ethical Guidelines ◽  
Animal Science ◽  
Ethical Implications ◽  
Ethical Policy ◽  
Physical Environments ◽  
Wide Range ◽  
And Performance

Animal science research is important in relation to our understanding of animals, their function and performance, and their relationships with their social and physical environments. Animal science research covers a wide range of disciplines and so can lead to the use of a variety of experimental techniques on animals for many different purposes. This has the potential to lead to a multitude of diverse ethical issues. Members of the British Society of Animal Science and authors of papers submitted to the Society for publication come from countries around the world and therefore are subject to differences in legislative requirements and recommendations regarding animal experimentation. These legal requirements, along with the ethical implications of the research must be fully considered before any experimental work is undertaken.

scholarly journals CFD Study of Nozzle Configurations for Ultra High Bypass Engines

1993 ◽  
Author(s):  
H. Zimmermann ◽  
R. Gumucio ◽  
K. Katheder ◽  
A. Jula
Keyword(s):  
Engine Performance ◽  
Operating Conditions ◽  
Aerodynamic Design ◽  
Thrust Coefficient ◽  
Optimum Range ◽  
Installation Effects ◽  
Wide Range ◽  
And Performance ◽  
Aircraft Aerodynamics ◽  
Bypass Ratio

Performance and aerodynamic aspects of ultra-high bypass ratio ducted engines have been investigated with an emphasis on nozzle aerodynamics. The interference with aircraft aerodynamics could not be covered. Numerical methods were used for aerodynamic investigations of geometrically different aft end configurations for bypass ratios between 12 and 18, this is the optimum range for long missions which will be important for future civil engine applications. Results are presented for a wide range of operating conditions and effects on engine performance are discussed. The limitations for higher bypass ratios than 12 to 18 do not come from nozzle aerodynamics but from installation effects. It is shown that using CFD and performance calculations an improved aerodynamic design can be achieved. Based on existing correlations, for thrust and mass-flow, or using aerodynamic tailoring by CFD and including performance investigations, it is possible to increase the thrust coefficient up to 1%.

Creating a growth mindset

2017 ◽  
Vol 16 (4) ◽  
pp. 155-160
Author(s):  
Ian Johnston
Keyword(s):  
Case Studies ◽  
Design Methodology ◽  
Growth Mindset ◽  
Cultural Space ◽  
Content Type ◽  
Fixed Mindset ◽  
And Performance

Purpose This paper aims to show that everything a business does is fundamentally reliant on its culture. Culture determines how successful a strategy is and whether that strategy can be executed. If the culture in a business is out of alignment, it is imperative to change it. This paper examines how HR professionals can take ownership of this cultural space and help to create a growth mindset throughout the organisation. Design/methodology/approach The paper is based on experience gained through working with several large organisations to transform their people culture and performance by embracing a growth mindset and to help their HR leadership become the early champions of change, thus ensuring the process was successfully delivered. The paper includes case studies of two organisations where successful cultural shaping delivered improved results. Findings Companies with a growth mindset will outperform those with a fixed mindset. Changing mindsets is not overly complex, but it requires flawless implementation with the HR leaders at the forefront. Originality/value As Lou Gerstner, who turned around the computing giant IBM, said “I finally realised that culture is not part of the game, it is the game”. By understanding how individual mindsets impact culture, HR professionals can own and drive their organisation’s culture-shaping efforts.

Design, implementation, and evaluation of an XG-PON module for the ns-3 network simulator

SIMULATION ◽  
2017 ◽  
Vol 93 (5) ◽  
pp. 409-426 ◽  
Author(s):  
Jerome A Arokkiam ◽  
Pedro Alvarez ◽  
Xiuchao Wu ◽  
Kenneth N Brown ◽  
Cormac J Sreenan ◽  
...  
Keyword(s):  
Optical Network ◽  
Future Internet ◽  
Access Networks ◽  
Passive Optical Network ◽  
Network Simulator ◽  
Optical Access Networks ◽  
Research Topics ◽  
Extensive Evaluation ◽  
Wide Range ◽  
And Performance

10-gigabit-capable Passive Optical Network (XG-PON), one of the latest standards of optical access networks, is regarded as one of the key technologies for future Internet access networks. This paper presents the design and evaluation of our XG-PON module for the ns-3 network simulator. This module is designed and implemented with the aim to provide a standards-compliant, configurable, and extensible module that can simulate XG-PON with reasonable speed and support a wide range of research topics. These include analyzing and improving the performance of XG-PON, studying the interactions between XG-PON and the upper-layer protocols, and investigating its integration with various wireless networks. In this paper, we discuss its design principles, describe the implementation details, and present an extensive evaluation on both functionality and performance.

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