Effects of Emulsified Fuel on the Performance and Emission Characteristics of Aeroengine Combustors

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
M. G. De Giorgi ◽  
E. Pescini ◽  
S. Campilongo ◽  
G. Ciccarella ◽  
D. Fontanarosa ◽  
...  
Keyword(s):  
Flame Structure ◽  
Combustion Process ◽  
Optical Filters ◽  
Diagnostic Techniques ◽  
Jet Fuels ◽  
Test Case ◽  
Performance And Emission ◽  
Emulsified Fuel ◽  
Spectral Ranges ◽  
The Impact

Abstract The aim of this work is the experimental investigation of the effects of the addition of water and urea into jet fuels, on the reduction of nitrogen oxides (NOx) emissions and eventually improvement of the lean flame stability in aeroengine combustors. Experiments have been carried out using a 300-kW liquid-fueled swirling combustor. Various urea and/or water concentrations have been tested at the same fuel/air ratio. In order to study the flame behavior, noninvasive optical diagnostic techniques, as charge-coupled device (CCD) cameras in different spectral ranges (visible and UV ranges, with different optical filters), have been adopted to analyze the shape and the brightness of the flame structure. Measurements of exhaust emissions (NOx, SO2, carbon monoxide (CO), CO2, and O2) have also been performed in order to evaluate the impact of emulsification on the entire combustion process. Finally, the thermal efficiency losses with respect to the neat jet test case were also analyzed for each emulsified fuel condition.

Effects of Emulsified Fuel on the Performance and Emission Characteristics of Aeroengine Combustors

2019 ◽  
Author(s):  
M. G. De Giorgi ◽  
E. Pescini ◽  
S. Campilongo ◽  
G. Ciccarella ◽  
D. Fontanarosa ◽  
...  
Keyword(s):  
Flame Structure ◽  
Combustion Process ◽  
Optical Filters ◽  
Diagnostic Techniques ◽  
Jet Fuels ◽  
Test Case ◽  
Performance And Emission ◽  
Emulsified Fuel ◽  
Spectral Ranges ◽  
The Impact

Abstract The aim of the present work is the experimental investigation of the effects of the addition of water and urea into jet fuels, on the reduction of nitrogen oxides (NOx) emissions and eventually improvement of the lean flame stability in aeroengine combustors. Experiments have been carried out using a 300-kW liquid-fueled swirling combustor. Various urea and/or water concentrations have been tested at the same fuel/air ratio. In order to study the flame behavior, non-invasive optical diagnostic techniques, as charge-coupled device (CCD) cameras in different spectral ranges (Visible and UV ranges, with different optical filters), have been adopted to analyze the shape and the brightness of the flame structure. Measurements of exhaust emissions (NOx, SO2, CO, CO2 and O2) have also been performed in order to evaluate the impact of emulsification on the entire combustion process. Finally, the thermal efficiency losses with respect to the neat jet test case were also analyzed for each emulsified fuel condition.

scholarly journals Influence of Eddy-Generation Mechanism on the Characteristic of On-Source Fire Whirl

2019 ◽  
Vol 9 (19) ◽  
pp. 3989 ◽  
Author(s):  
Cheng Wang ◽  
Anthony Chun Yin Yuen ◽  
Qing Nian Chan ◽  
Timothy Bo Yuan Chen ◽  
Qian Chen ◽  
...  
Keyword(s):  
Flame Structure ◽  
Flame Temperature ◽  
Combustion Process ◽  
Flame Height ◽  
Reacting Flow ◽  
Detailed Chemistry ◽  
Eddy Generation ◽  
Fire Whirl ◽  
Generation Mechanisms ◽  
The Impact

This paper numerically examines the characterisation of fire whirl formulated under various entrainment conditions in an enclosed configuration. The numerical framework, integrating large eddy simulation and detailed chemistry, is constructed to assess the whirling flame behaviours. The proposed model constraints the convoluted coupling effects, e.g., the interrelation between combustion, flow dynamics and radiative feedback, thus focuses on assessing the impact on flame structure and flow behaviour solely attribute to the eddy-generation mechanisms. The baseline model is validated well against the experimental data. The data of the comparison case, with the introduction of additional flow channelling slit, is subsequently generated for comparison. The result suggests that, with the intensified circulation, the generated fire whirl increased by 9.42 % in peak flame temperature, 84.38 % in visible flame height, 6.81 % in axial velocity, and 46.14 % in velocity dominant region. The fire whirl core radius of the comparison case was well constrained within all monitored heights, whereas that of the baseline tended to disperse at 0.5   m height-above-burner. This study demonstrates that amplified eddy generation via the additional flow channelling slit enhances the mixing of all reactant species and intensifies the combustion process, resulting in an elongated and converging whirling core of the reacting flow.

scholarly journals Advanced Classical Optical Filters with Three Waveguide Coupled Sagnac Loop Reflectors

2021 ◽  
Author(s):  
Hamed Arianfard ◽  
Jiayang Wu ◽  
Saulius Juodkazis ◽  
David Moss
Keyword(s):  
High Performance ◽  
Structural Parameters ◽  
Spectral Response ◽  
Optical Filters ◽  
Practical Applications ◽  
Design And Optimization ◽  
Fabrication Tolerances ◽  
Spectral Ranges ◽  
The Impact ◽  
Mode Interference

Abstract We theoretically investigate advanced multi-functional integrated photonic filters formed by three waveguide coupled Sagnac loop reflectors (3WC-SLRs). By tailoring the coherent mode interference, the spectral response of the 3WC-SLR resonators is engineered to achieve diverse filtering functions with high performance. These include optical analogues of Fano resonances that yield ultrahigh spectral extinction ratios (ERs) and slope rates, resonance mode splitting with high ERs and low free spectral ranges, and classical Butterworth, Bessel, Chebyshev, and elliptic filters. A detailed analysis of the impact of the structural parameters and fabrication tolerances is provided to facilitate device design and optimization. The requirements for practical applications are also considered. These results theoretically verify the effectiveness of using 3WC-SLR resonators as multi-functional integrated photonic filters for flexible spectral engineering in diverse applications.

scholarly journals Modeling diesel combustion with tabulated kinetics and different flame structure assumptions based on flamelet approach

2019 ◽  
Vol 21 (1) ◽  
pp. 89-100 ◽  
Author(s):  
Tommaso Lucchini ◽  
Daniel Pontoni ◽  
Gianluca D’Errico ◽  
Bart Somers
Keyword(s):  
Soot Formation ◽  
Flame Structure ◽  
Combustion Process ◽  
Computational Cost ◽  
Pollutant Emissions ◽  
Diesel Combustion ◽  
Flamelet Generated Manifold ◽  
Tabulated Chemistry ◽  
Computational Fluid Dynamics Analysis ◽  
The Impact

Computational fluid dynamics analysis represents a useful approach to design and develop new engine concepts and investigate advanced combustion modes. Large chemical mechanisms are required for a correct description of the combustion process, especially for the prediction of pollutant emissions. Tabulated chemistry models allow to reduce significantly the computational cost, maintaining a good accuracy. In the present work, an investigation of tabulated approaches, based on flamelet assumptions, is carried out to simulate turbulent Diesel combustion in the Spray A framework. The Approximated Diffusion Flamelet is tested under different ambient conditions and compared with Flamelet Generated Manifold, and both models are validated with Engine Combustion Network experimental data. Flame structure, combustion process and soot formation were analyzed in this work. Computed results confirm the impact of the turbulent–chemistry interaction on the ignition event. Therefore, a new look-up table concept Five-Dimensional-Flamelet Generated Manifold, that accounts for an additional dimension (strain rate), has been developed and tested, giving promising results.

scholarly journals Three Coupled Waveguide Sagnac Loop Reflectors for High Performance Integrated Optical Filters

2020 ◽  
Author(s):  
David Moss
Keyword(s):  
High Performance ◽  
Structural Parameters ◽  
Spectral Response ◽  
Optical Filters ◽  
Practical Applications ◽  
Design And Optimization ◽  
Integrated Optical ◽  
Fabrication Tolerances ◽  
Spectral Ranges ◽  
The Impact

<p><b>We theoretically investigate advanced multi-functional integrated photonic filters formed by three waveguide coupled Sagnac loop reflectors (3WC-SLRs). By tailoring the coherent mode interference, the spectral response of the 3WC-SLR resonators is engineered to achieve diverse filtering functions with high performance. These include optical analogues of Fano resonances that yield ultrahigh spectral extinction ratios (ERs) and slope rates, resonance mode splitting with high ERs and low free spectral ranges, and classical Butterworth, Bessel, Chebyshev, and elliptic filters. A detailed analysis of the impact of the structural parameters and fabrication tolerances is provided to facilitate device design and optimization. The requirements for practical applications are also considered. These results theoretically verify the effectiveness of using 3WC-SLR resonators as multi-functional integrated photonic filters for flexible spectral engineering in diverse applications.</b></p>

scholarly journals Emission Controls Using Different Temperatures of Combustion Air

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Radovan Nosek ◽  
Michal Holubčík ◽  
Štefan Papučík
Keyword(s):  
Heat Source ◽  
Air Temperature ◽  
Combustion Process ◽  
Maximum Efficiency ◽  
Heat Sources ◽  
Energy Transformation ◽  
Performance And Emission ◽  
Emission Controls ◽  
Different Temperatures ◽  
The Impact

The effort of many manufacturers of heat sources is to achieve the maximum efficiency of energy transformation chemically bound in the fuel to heat. Therefore, it is necessary to streamline the combustion process and minimize the formation of emission during combustion. The paper presents an analysis of the combustion air temperature to the heat performance and emission parameters of burning biomass. In the second part of the paper the impact of different dendromass on formation of emissions in small heat source is evaluated. The measured results show that the regulation of the temperature of the combustion air has an effect on concentration of emissions from the combustion of biomass.

Instability Control by Premixed Pilot Flames

2008 ◽  
Author(s):  
Peter Albrecht ◽  
Stefanie Bade ◽  
Arnaud Lacarelle ◽  
Christian Oliver Paschereit ◽  
Ephraim Gutmark
Keyword(s):  
Gas Turbines ◽  
Flame Structure ◽  
Premixed Flames ◽  
Combustion Process ◽  
Operating Conditions ◽  
Combustion Stability ◽  
Pilot Injection ◽  
Acoustic Instabilities ◽  
Flame Behavior ◽  
The Impact

Premixed flames of swirl-stabilized combustors (displaced-half-cone) are susceptible to thermo-acoustic instabilities which should be avoided under all operating conditions in order to guarantee a long service life for both stationary and aircraft gas turbines. The source of this unstable flame behavior can e.g. be found in a transition of the premix flame structure between two stationary conditions that can be easily excited by fuel fluctuations, coherent structures within the flow and other methods. Pilot flames can alleviate this issue by either improving the dynamic stability directly or by sustaining the main combustion process at operating points where instabilities are unlikely. In the present study, the impact of two different premixed pilot injection on the combustion stability is investigated. One of the pilot injector (pilot flame injector, PFI) was located upstream of the recirculation zone at the apex of the burner. The second one was a pilot ring (PR) placed at the burner outlet on the dump plane. A noticeable feature of the pilot injector was that an ignition device allowed for creating pilot premixed flames. The present investigation evidenced that these premixed pilot flames were able to suppress instabilities over a wider fuel/air ratio range than when the conventional premixed pilot injection alone. Furthermore, it was possible to prevent instabilities and maintain the flame burning near the lean blow out when a percentage of the fuel was premixed with air and injected through the pilot ring. In the mean time, NOx emissions were significantly reduced.

scholarly journals Three Coupled Waveguide Sagnac Loop Reflectors for High Performance Integrated Optical Filters

2020 ◽  
Author(s):  
David Moss
Keyword(s):  
High Performance ◽  
Structural Parameters ◽  
Spectral Response ◽  
Optical Filters ◽  
Practical Applications ◽  
Design And Optimization ◽  
Integrated Optical ◽  
Fabrication Tolerances ◽  
Spectral Ranges ◽  
The Impact

<p><b>We theoretically investigate advanced multi-functional integrated photonic filters formed by three waveguide coupled Sagnac loop reflectors (3WC-SLRs). By tailoring the coherent mode interference, the spectral response of the 3WC-SLR resonators is engineered to achieve diverse filtering functions with high performance. These include optical analogues of Fano resonances that yield ultrahigh spectral extinction ratios (ERs) and slope rates, resonance mode splitting with high ERs and low free spectral ranges, and classical Butterworth, Bessel, Chebyshev, and elliptic filters. A detailed analysis of the impact of the structural parameters and fabrication tolerances is provided to facilitate device design and optimization. The requirements for practical applications are also considered. These results theoretically verify the effectiveness of using 3WC-SLR resonators as multi-functional integrated photonic filters for flexible spectral engineering in diverse applications.</b></p>

scholarly journals Costs to Reduce the Human Health Toxicity of Biogas Engine Emissions

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6360
Author(s):  
Alberto Benato ◽  
Alarico Macor
Keyword(s):  
Human Health ◽  
Internal Combustion Engines ◽  
Impact Analysis ◽  
Combustion Engine ◽  
Combustion Process ◽  
Internal Combustion ◽  
Health Impact ◽  
Test Case ◽  
Disability Adjusted Life ◽  
The Impact

The anaerobic digestion of biodegradable substrates and waste is a well-known process that can be used worldwide to produce a renewable fuel called biogas. At the time of writing, the most widespread way of using biogas is its direct usage in combined heat and power internal combustion engines (CHP-ICEs) to generate electricity and heat. However, the combustion process generates emissions, which in turn have an impact on human health. Therefore, there is a need to: (i) measure the ICE emissions (both regulated and unregulated), (ii) compute the impact on human health, (iii) identify the substances with the highest impact and (iv) calculate the avoided damage to human health per Euro of investment in technology able to abate the specific type of pollutant. To this end, the authors conducted an experimental campaign and selected as a test case a 999 kWel biogas internal combustion engine. Then, the collected data, which included both regulated and unregulated emissions, were used to calculate the harmfulness to human health and identify the more impactful compounds. Thus, combining the results of the impact analysis on human health and the outcomes of a market analysis, the avoided damage to human health per Euro of investment in an abatement technology was computed. In this manner, a single parameter, expressed in DALY -1, provided clear information on the costs to reduce each disability-adjusted life year (DALY). The impact analysis on human health, which was performed using the Health Impact Assessment, showed that NOx was the main contributor to damage to human health (approximately 91% of the total), followed by SOx (6.5%), volatile organic compounds (1.4%) and CO (0.7%). Starting from these outcomes, the performed investigation showed that the technology that guarantees the maximum damage reduction per unit of cost is the denitrification system or the oxidizing converter, depending on whether the considered plant is already in-operation or newly built. This is an unexpected conclusion considering that the most impacting emission is the NOx.

Instability Control by Premixed Pilot Flames

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Peter Albrecht ◽  
Stefanie Bade ◽  
Arnaud Lacarelle ◽  
Christian Oliver Paschereit ◽  
Ephraim Gutmark
Keyword(s):  
Gas Turbines ◽  
Flame Structure ◽  
Premixed Flames ◽  
Combustion Process ◽  
Operating Conditions ◽  
Combustion Stability ◽  
Lean Blowout ◽  
Acoustic Instabilities ◽  
Flame Behavior ◽  
The Impact

Premixed flames of swirl-stabilized combustors (displaced half-cone) are susceptible to thermo-acoustic instabilities, which should be avoided under all operating conditions in order to guarantee a long service life for both stationary and aircraft gas turbines. The source of this unstable flame behavior can be found in a transition of the premix flame structure between two stationary conditions that can be easily excited by fuel fluctuations, coherent structures within the flow, and other mechanisms. Pilot flames can alleviate this issue either by improving the dynamic stability directly or by sustaining the main combustion process at operating points where instabilities are unlikely. In the present study, the impact of two different premixed pilot injections on the combustion stability is investigated. One of the pilot injector (pilot flame injector) was located upstream of the recirculation zone at the apex of the burner. The second one was a pilot ring placed at the burner outlet on the dump plane. A noticeable feature of the pilot injector was that an ignition device allowed for creating pilot premixed flames. The present investigation showed that these premixed pilot flames were able to suppress instabilities over a wider fuel/air ratio range than the conventional premixed pilot injection alone. Furthermore, it was possible to prevent instabilities and maintain the flame burning near the lean blowout when a percentage of the fuel was premixed with air and injected through the pilot ring. NOx emissions were significantly reduced.

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