Soot, Flow Field, and Spray Structure in Turbulent Swirl-Stabilized Spray Flames of Jet A-1/Biofuel Blends in a Model Gas Turbine Combustor PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Soot, Flow Field, and Spray Structure in Turbulent Swirl-Stabilized Spray Flames of Jet A-1/Biofuel Blends in a Model Gas Turbine Combustor PDF full book. Access full book title Soot, Flow Field, and Spray Structure in Turbulent Swirl-Stabilized Spray Flames of Jet A-1/Biofuel Blends in a Model Gas Turbine Combustor by Taylor Rault. Download full books in PDF and EPUB format.
Author: Taylor Rault
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Get Book Here
Book Description
The effects of ethanol, n-butanol, and m-xylene addition to swirl-stabilized Jet A-1 spray flames were investigated in a model combustor with 94 mm x 94 mm cross-section and 188 mm length. Dopants were added in concentrations up to 20% by energy content for a 10 kW total thermal output; two air flow rates were used for each blend. Droplet size distributions, time-averaged flow fields, as well as time-averaged soot volume fractions and primary particle sizes were measured using the Fraunhofer diffraction technique, stereoscopic particle image velocimetry, and auto-compensating laser-induced incandescence, respectively. Measurable differences in spray distributions and flow fields were observed for all additives compared to neat Jet A-1. In all blend flames, an additional time-averaged soot volume fraction peak absent for neat Jet A-1 was observed below 30 mm above the combustor base. While total soot loading generally increased with ethanol and m-xylene addition, it decreased with n-butanol addition.
Author: Taylor Rault
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Get Book Here
Book Description
The effects of ethanol, n-butanol, and m-xylene addition to swirl-stabilized Jet A-1 spray flames were investigated in a model combustor with 94 mm x 94 mm cross-section and 188 mm length. Dopants were added in concentrations up to 20% by energy content for a 10 kW total thermal output; two air flow rates were used for each blend. Droplet size distributions, time-averaged flow fields, as well as time-averaged soot volume fractions and primary particle sizes were measured using the Fraunhofer diffraction technique, stereoscopic particle image velocimetry, and auto-compensating laser-induced incandescence, respectively. Measurable differences in spray distributions and flow fields were observed for all additives compared to neat Jet A-1. In all blend flames, an additional time-averaged soot volume fraction peak absent for neat Jet A-1 was observed below 30 mm above the combustor base. While total soot loading generally increased with ethanol and m-xylene addition, it decreased with n-butanol addition.
Author: Lu-Yin Wang
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
Get Book Here
Book Description
Soot formation and evolution in relation with the flow fields were investigated experimentally in turbulent swirl-stabilized non-premixed flames using three different fuels: methane, ethanol and aviation Jet A-1. The studied flames were confined and stabilized in a model gas turbine combustor with a swirl number of ~0.55. Soot volume fraction, fv, and primary soot particle size, dp, were measured using auto-compensating laser-induced incandescence, and planar three-component velocity fields were measured using stereoscopic particle image velocimetry. Measurements of planar laser-induced fluorescence of OH and OH* chemiluminescence were also made for methane and ethanol flames. The OH* field was further Abel-inverted to qualitatively locate the heat release zone. The flow field for all flames featured pronounced inner and outer recirculation zones (IRZ, ORZ), each bounded by their corresponding inner and outer shear layers (ISL, OSL). Abel-inverted OH* intensity maps showed that primary reaction zones occurred in the vicinity of ISL. The central fuel jet penetrating into the IRZ accompanied by a stagnation zone was observed in all methane flames. Soot measurements showed that the overall dp for methane and Jet A-1 flames ranged between 30 nm and 60 nm without discernible trends. In methane flames, peak time-averaged fv occurred between the central jet penetration and the ISL. The decrease and the final disappearance of time-averaged fv were strongly correlated with elevated OH, demonstrating a dominant oxidative attack of OH on soot. With a ~7% increase in air flow rate, the level of soot volume fraction dropped by nearly threefold due to enhanced turbulence intermittency. The appearance of ethanol spray flames, which lacked a bright yellow color, largely differed from others. The absence of soot was confirmed in the laser-induced incandescence measurements. The isothermal flow field of ethanol flames exhibited a large-scale structure of precessing vortex core which was then suppressed under reacting conditions. In Jet A-1 flames, spray pattern changed from V-shaped hollow cone to semi-solid cone when air flow rate increased by 20%, resulting in a 60% reduction in peak time-averaged fv. In contrast to results obtained from the methane flame, soot was found primarily outside the ISL where fuel existed in abundance.
Author: David G. Lilley
Publisher: DIANE Publishing
ISBN: 1428993428
Category :
Languages : en
Pages : 97
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 28
Get Book Here
Book Description
Author: Alessandro Parente
Publisher: Frontiers Media SA
ISBN: 2889717003
Category : Technology & Engineering
Languages : en
Pages : 160
Get Book Here
Book Description
Author: Paul A. Libby
Publisher:
ISBN:
Category : Combustion
Languages : en
Pages : 12
Get Book Here
Book Description
Author: Benjamin Mathews
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Gas turbine combustion systems, such as those used for aircraft propulsion and power generation, are susceptible to a phenomenon known as combustion instabilities. Combustion instabilities can result in reduced engine operability, structural fatigue, and in extreme circumstances, catastrophic engine failure. Due to increased regulations on pollutant emissions, systems such as gas turbines are forced to run at fuel lean conditions with premixing. These operating conditions, while effective at reducing emissions, make the system more susceptible to combustion instabilities and therefore research into the combustion instability phenomena is as important as ever.Prior research has identified vorticity fluctuations as an important coupling mechanism present during velocity-coupled combustion instabilities in swirl-stabilized flames, which is a common stabilization method used in gas turbines. These vorticity fluctuations can be induced by longitudinal acoustic pressure oscillations that are convected across the swirler and dump plane upstream of the flame. While these vorticity fluctuations have been identified in a number of configurations using both experimental and simulation techniques, the sensitivity of this mechanism to flow configuration and boundary conditions has not been studied parametrically.In this study, we investigate the impact of time-averaged swirl level, forcing frequency and amplitude on vorticity fluctuation dynamics in the azimuthal direction of a non-reacting swirling jet with and without confinement. The goal of this work is to better understand the dependence of vorticity fluctuations on these various parameters as well as the vorticity conversion processes that occur in the flow. We have shown that vorticity fluctuation levels vary with time-averaged swirl number, particularly in the presence of a self-excited precessing vortex core, which reduces the flow receptivity to the acoustically forced fluctuations. Additionally, variations in forcing frequency and amplitude excite flow response in different portions of the flow, particularly for different swirl numbers with and without confinement. The implications of these results are discussed and future work is proposed.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 98
Get Book Here
Book Description
The focus of this study is to investigate the emission characteristics and combustion dynamics of multiple swirl spray combustors either in premixing or non-premixed combustion (e.g. Lean Direct Injection), and correlate these combustion characteristics (emissions, combustion instability and lean flammability) to the fluids dynamics (flow structures and its evolution). This study covers measurement of velocity flow field, temperature field, and combustion under effects of various parameters, including inlet flow Reynolds number, inlet air temperature, swirl configurations, downstream exhaust nozzle contraction ratios, length of mixing tube. Knowledge obtained through this comprehensive study is applied to passive and active controls for improving gas turbine combustion performance in the aid of novel sensor and actuator technologies.
Author: Bruce Tobis
Publisher:
ISBN:
Category : Combustion
Languages : en
Pages : 170
Get Book Here
Book Description
Author: Timothy C. Lieuwen
Publisher: Cambridge University Press
ISBN: 052176405X
Category : Science
Languages : en
Pages : 385
Get Book Here
Book Description
The development of clean, sustainable energy systems is a preeminent issue in our time. Gas turbines will continue to be important combustion-based energy conversion devices for many decades to come, used for aircraft propulsion, ground-based power generation, and mechanical-drive applications. This book compiles the key scientific and technological knowledge associated with gas turbine emissions into a single authoritative source.
