Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 19 of 19 for “"Laser-Induced Incandescence"”.
-
Laser-induced incandescence for soot diagnostics at high pressure
This work focuses on laser-induced incandescence (LII) at elevated pressure. LII is a laser-based technique for measuring particle sizes and volume fractions of nano-sized particles in aerosols. These particles, as emitted by traffic in the form of soot, cause a significant health risk, as …
-
Laser induced incandescence imaging for the investigation of soot formation in laminar flames
This work has been aimed at applying laser induced incandescence imaging for the measurement of soot concentration within a variety of novel flame sources and setups. Laser induced incandescence (LII) is an optical technique used in laser diagnostics to measure soot volume fraction and estimate …
-
On the Use of Laser-Induced Incandescence for Soot Diagnostics: From Theoretical Aspects to Applications in Engines
The laser-induced incandescence technique (LII) is a laser-based diagnostic technique for measurements of soot volume fraction and particle size. The technique relies on detection of incandescent light from soot particles heated to around 4000 K using nanosecond laser pulses. A theoretical model …
-
Laser Induced Incandescence for Volume Fraction and Relative Particle Size Measurements in a Rich-Quench-Lean Jet A Combustor
… relative soot particle size distribution using laser-induced incandescence (LII) diagnostics inside a three-sector rich-quench-lean (RQL) aeroengine combustor running with Jet A fuel. First, the setup is described including details of the combustor, pressure vessel, data acquisition system, …
-
Flow Field and Soot Formation Characteristics in Swirl-stabilized Non-premixed Turbulent Flames
… 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 …
-
Development Of A Two-Color Optical Diagnostic For The Determination Of Engine In-Cylinder Soot Temperature And Volume Fraction Evolution With A Flame-Calibrated Emissivity Model
… illumination, and the limitations imposed by laser repetition rates hinder the utilization of most of these diagnostics. The final technique, soot two-color thermometry, is less affected by the above factors, and therefore, has been widely utilized in diesel engine studies. This work presents …
-
Novel diode laser absorption techniques for combustion diagnostics
… such as gas chromatography. In this thesis two laser absorption measurement techniques are applied to measure the soot distribution, and acetylene concentration profiles in a flat-flame burner. The in-situ measurement of the distribution of particulate matter in flames is a key step in …
-
Laser diagnostics of soot in hydrocarbon diffusion flames
Driven by the demand for soot-free combustion, laser-based diagnostic techniques on soot have been developing since the late 1980s. One of these techniques is line-of- sight extinction, which is a fast, low-cost, and quantitative method to investigate the soot volume fraction in flames. However, …
-
Pyrolysis oil combustion characteristics and exhaust emissions in a swirl-stabilized flame
… speed imaging of flame luminosity and several laser diagnostic methods including Mie scattering, hydroxyl radical planar induced fluorescence (OH-PLIF), fuel planar laser-induced fluorescence (Fuel-PLIF), and laser induced incandescence (LII). Spray characteristics have been investigated by …
-
Spectroscopic measurements and modeling of carbonaceous particle combustion in a shock tube
… models are performed by applying current laser-induced incandescence and multiphase flow models, which couple particle optical signatures to energy- and mass-balance equations. Models reproduce observed trends across varying temperature and pressure conditions, although they tend to …
-
Heat Transfer and Combustion Characteristics of Nano-Sized Aluminum and Aluminum Oxide Utilizing Advanced Laser and Optical Diagnostics
… utilizing a two-colored time-resolved Laser-Induced Incandescence technique (TiRe-LII). The model’s validity was confirmed by comparing it with data from existing literature. This model serves as a reliable foundation for measuring the accommodation coefficient in future studies …
-
In-Cylinder Soot Oxidation in an Optically Accessible Automotive Diesel Engine
… process. In this regard, various optical/laser-based imaging diagnostics were performed to unveil the development of high-temperature reaction and soot in small-bore optical diesel engines, which include OH* chemiluminescence, planar laser-induced fluorescence of hydroxyl (OH-PLIF) and …
-
Mixing and Combustion Studies in an Optically-Accessible Small-Bore High-Speed Direct -Injection Diesel Engine
… and first injection timings and quantities. Laser-induced exciplex fluorescence was used to obtain simultaneous liquid and vapor fuel distributions within the combustion chamber. In addition, high-speed video was used to study the injector and spray behavior. Results showed that the liquid …
-
Dynamics of nanoparticle combustion
… mechanism in the simple model. Time-resolved laser induced incandescence measurements were performed to measure the accommodation coefficient of nano-alumina particles in various gaseous environments. The accommodation coefficient was found to be 0.03, 0.07, and 0.15 in helium, nitrogen, and …
-
Sooting behaviour of turbulent non-premixed jet flames.
Soot measurements using planar laser-induced incandescence (LII) have been performed in three commercial propane-fired flames produced by simple jet (SJ), precessing jet (PJ-P) and bluff-body jet (BB) burners. The flames span a wide range of different global mixing rates for the same nozzle …
-
Thermographic particle image velocimetry: from phosphorescence to incandescence
… for this technique are: (a) it requires two lasers and three cameras running simultaneously, making it a high-cost technique; (b) several recent studies reported the multiple scattering effects for gas-phase phosphor thermometry, which may severely bias the temperature measurement for certain …
-
The effects of molecular structures and reactant temperatures on soot formation in a coflow laminar flame
The objective of the present study is to explore the effects of aromatic hydrocarbons and reactant temperatures on soot formation in a coflow diffusion flame. The study is motivated by the observation that soot formation is influenced by the flame boundary and ambient conditions, i.e. fuel species, …
-
Simulating high flux solar radiation and assessing its influence on a sooty flame
… temperature in a laminar sooty flame. Detailed laser diagnostics was performed on a laminar sooty flame with and without the irradiance of CSR, because laser diagnostics are demonstrated to hold the advantages of being non-intrusive, lower interferences and of being applicable to environments …
-
Understanding the development of a reacting fuel jet inside an automotive-size diesel engine using optical and laser-based diagnostics
… the burst-pressure of quartz windows. Planar laser-induced fluorescence imaging of hydroxyl (OH-PLIF), fuel-PLIF, and line-of-sight integrated chemiluminescence imaging were performed for various combustion stages identified by the in-cylinder pressure traces and apparent heat release rates. …