Soot Formation and Emission From Jet A-1 and a 30% HEFA Blend in a Multisector Combustor at Realistic Operating Conditions

2020 ◽  
Author(s):  
Christoph Hassa ◽  
Eggert Magens ◽  
Lena Voigt ◽  
Olaf Diers ◽  
Ingo Otterpohl ◽  
...  
Keyword(s):  
Soot Formation ◽  
Operating Conditions ◽  
Fuel Load ◽  
Soot Concentration ◽  
Scanning Mobility Particle Sizer ◽  
Primary Zone ◽  
Soot Mass ◽  
Laser Induced Incandescence ◽  
Particle Sizer ◽  
Laser Extinction

Abstract The production and emission of soot from Kerosene JET-A1 and a blend of a different JET-A1 and 30% HEFA was investigated in a realistic multisector combustor of Rolls-Royce Deutschland. Soot concentration measurements were performed at the exit as well as in the optically accessible primary zone of the combustor. There, information of soot mass concentration is available from measurements using Laser induced incandescence and Laser extinction. At the exit of the combustor, soot particles were measured with a scanning mobility particle sizer. This resulted in particle size distributions from which soot number and mass concentrations were calculated. Within the pressurized combustor, low load points, scaled cruise and high load points were operated. For the investigated operating range which reaches to ∼50% of max pressure but preserves engine AFR, up to 75% reduction of both soot particle mass and number EI were observed for the HEFA blend in part load and 50% at the scaled high-power condition. However at the end of the primary zone, a reduction increasing with soot concentration and fuel load was recorded. This guides attention to the different oxidation characteristics for the fuels in the investigated combustor. Accordingly, larger particles were consistently measured at the exit for the HEFA blend.

A Semi-Empirical Model to Predict Aircraft Soot Emission in Rich Zone of RQL Combustor

2015 ◽  
Author(s):  
Kyung Hak Choo ◽  
Sangmin Lee ◽  
Russell K. Denney ◽  
Dimitri N. Mavris
Keyword(s):  
Conceptual Design ◽  
Empirical Model ◽  
Soot Formation ◽  
Turbulent Flame ◽  
Operating Conditions ◽  
Particulate Emissions ◽  
Soot Emission ◽  
Primary Zone ◽  
Reactor Networks ◽  
Semi Empirical

The reduction of particulate matter emissions is becoming a requirement for aircraft turbine engine combustor design. This requirement leads to the need to estimate particulate emissions during the conceptual design phase. Current prediction methods are based on detailed numerical simulation techniques such as CFD, which are unsuitable for conceptual design due to high computational cost. This paper introduces a new approach employing a semi-empirical model for prediction of the soot emission indices of RQL combustors. The proposed approach dramatically improves computational efficiency by avoiding complex numerical calculations. The model is based on the response surface developed from experimental data for turbulent non-premixed flames. The data has been extracted from the literature, employing statistical methods such as machine learning techniques and polynomial regressions to apply the turbulent flame data to the actual operating conditions in the primary zone of aircraft engine combustors. The model is developed by first representing the combustor primary zone by chemical reactor networks constructed in CHEMKIN based on a statistical PDF approach to simulate the non-uniform distribution of time-evolving local mixture fraction with a beta distribution. The reactor networks are used to estimate the concentrations of soot precursor species in the rich zone. The empirical equations are then used with the predicted concentrations to predict the soot formation rate. Finally, these results are used along with the turbulent non-premixed flame data to develop the final model through a model calibration process.

Soot Formation and Its Effect in an Aero Gas Turbine Combustor

2019 ◽  
Vol 36 (1) ◽  
pp. 61-73 ◽  
Author(s):  
R. K. Mishra ◽  
Sunil Chandel
Keyword(s):  
Gas Turbine ◽  
Equivalence Ratio ◽  
Soot Formation ◽  
Cone Angle ◽  
Peak Temperature ◽  
Soot Concentration ◽  
Gas Turbine Combustor ◽  
Spray Cone ◽  
Primary Zone ◽  
Soot Deposit

Abstract Soot formation and the effect of soot deposit on the performance and integrity on an aero gas turbine combustor has been studied. Defective atomizer or blockage of air passages creates a fuel rich mixture which promotes soot formation in combustor primary zone. The temperature field and soot concentration inside the liner has been analyzed at high equivalence ratio using computational model in CFX. The peak temperature in primary zone increases till equivalence ratio reaches ϕ=1.1. But at high equivalence ratio, i. e., ϕ≥1.2, the peak temperature in primary zone decreases and that in dilution zone increases. Soot concentration increases at liner front end as well as in dilution zone when equivalence ratio increases from 1.25 to 3.0. Erosion and distortion of atomizer flow passages cause higher spray cone angle which again increases the soot concentration. Soot deposit inside liner has detrimental effect on the life and performance of the combustor as well as of the aero engine.

A Standard Burner for High Pressure Laminar Premixed Flames: Detailed Soot Diagnostics

2015 ◽  
Vol 229 (5) ◽  
Author(s):  
Martin Leschowski ◽  
Thomas Dreier ◽  
Christof Schulz
Keyword(s):  
High Pressure ◽  
Soot Formation ◽  
Premixed Flames ◽  
Time Resolved ◽  
Volume Fractions ◽  
Signal Decay ◽  
Transmission Electron ◽  
Laser Induced Incandescence ◽  
Spectrally Resolved ◽  
Laser Extinction

AbstractSoot formation and oxidation in high-pressure combustion is of high practical relevance but still sparsely investigated because of its experimental complexity. In this work we present a high-pressure burner for studying sooting premixed flames at pressures up to 30 bar. An optically accessible vessel houses a burner that stabilizes a rich premixed ethylene/air flame on a porous sintered stainless-steel plate. The flame is surrounded by a non-sooting rich methane/air flame and an air coflow for reducing temperature gradients, buoyancy-induced instabilities, and heat loss of the innermost flame. Spectrally-resolved soot pyrometry was used for determining gas temperatures. These were introduced into model functions to fit the temporal signal decay curves obtained from two-color time-resolved laser-induced incandescence (TiRe-LII) measurements for extracting soot volume fractions and mean particle size as a function of height above burner and gas pressure. The derived mean particle sizes and soot concentrations were compared against thermophoretically sampled soot analyzed via transmission electron microscopy (TEM) and laser extinction measurements at 785 nm, respectively. Soot volume fractions derived from LII peak signal intensities need to be corrected for signal attenuation at the high soot concentrations present in the investigated flame. From the various heat conduction models employed in deriving mean soot particle diameters from TiRe-LII, the Fuchs model gave remarkably good agreement with TEM on sampled soot at various heights above the burner.

scholarly journals Optical study on characteristics of non-reacting and reacting diesel spray with different strategies of split injection

2018 ◽  
Vol 20 (6) ◽  
pp. 606-623 ◽  
Author(s):  
Jose M Desantes ◽  
José M García-Oliver ◽  
Antonio García ◽  
Tiemin Xuan
Keyword(s):  
High Speed ◽  
Dwell Time ◽  
Soot Formation ◽  
Operating Conditions ◽  
Split Injection ◽  
Injection Duration ◽  
Soot Mass ◽  
Lift Off ◽  
Combustion Processes ◽  
Injection Strategies

Even though studies on split-injection strategies have been published in recent years, there are still many remaining questions about how the first injection affects the mixing and combustion processes of the second one by changing the dwell time between both injection events or by the first injection quantity. In this article, split-injection diesel sprays with different injection strategies are investigated. Visualization of n-dodecane sprays was carried out under both non-reacting and reacting operating conditions in an optically accessible two-stroke engine equipped with a single-hole diesel injector. High-speed Schlieren imaging was applied to visualize the spray geometry development, while diffused background-illumination extinction imaging was applied to quantify the instantaneous soot production (net result of soot formation and oxidation). For non-reacting conditions, it was found that the vapor phase of second injection penetrates faster with a shorter dwell time and independently of the duration of the first injection. This could be explained in terms of one-dimensional spray model results, which provided information on the local mixing and momentum state within the flow. Under reacting conditions, interaction between the second injection and combustion recession of the first injection is observed, resulting in shorter ignition delay and lift-off compared to the first injection. However, soot production behaves differently with different injection strategies. The maximum instantaneous soot mass produced by the second injection increases with a shorter dwell time and with longer first injection duration.

scholarly journals Analyse der Partikelbildung aus der Elektrospray‐Flammensprühpyrolyse mittels Scanning Mobility Particle Sizer

2021 ◽  
Author(s):  
Malte Bierwirth ◽  
Vinzent Olszok ◽  
Varun Aiyar Ganesan ◽  
Jalal Poostforooshan ◽  
Alfred P. Weber
Keyword(s):  
Scanning Mobility Particle Sizer ◽  
Particle Sizer
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