Effects of Fuel Nozzle Displacement on Pre-Filming Airblast Atomization

1999 ◽  
Vol 123 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Y. M. Han ◽  
W. S. Seol ◽  
D. S. Lee ◽  
V. I. Yagodkin ◽  
I. S. Jeung
Keyword(s):  
Gas Phase ◽  
Flow Characteristics ◽  
Liquid Sheet ◽  
Diagnostic Methods ◽  
Number Density ◽  
Spray Structure ◽  
Optical Diagnostic ◽  
Size Number ◽  
Optimum Arrangement ◽  
Fuel Nozzle

In gas turbine combustors, optimum arrangement between a fuel nozzle and a swirler/prefilmer module must be sought to achieve satisfactory ignition and stability characteristics in addition to reduced level of emissions. However, due to thermal expansion of the combustor or misalignment of the fuel nozzle, the location of a fuel nozzle may vary. Displacement of a fuel nozzle may change the amount of fuel injected to the pre-filming device (usually the inner swirler wall) and the location of attachment, which in turn affects the thickness of pre-filming liquid sheet on the wall. As a result, the spray structure formed by pre-filming airblast atomization may be significantly changed. An experimental investigation is carried out to study the effects of fuel nozzle displacement on the structure of a spray formed by a dual orifice pressure atomizer and a counter-rotating dual swirler. The inner wall of the swirler is designed to be used as a pre-filming device. The behavior of droplets, the flow characteristics of the swirling air flow, and the interaction between droplets and the flow are studied. Optical diagnostic methods including a flow visualization and an Adaptive Phase/Doppler technique are used. Distributions of droplet size, number density, and liquid phase volume flux are presented for various fuel nozzle displacements, in addition to gas phase velocity.

scholarly journals Effects of Fuel Nozzle Displacement on Pre-Filming Airblast Atomization

1998 ◽  
Author(s):  
Yeoung Min Han ◽  
Woo Seok Seol ◽  
Dae Sung Lee ◽  
Victor I. Yagodkin ◽  
In Seuck Jeung
Keyword(s):  
Gas Phase ◽  
Flow Characteristics ◽  
Liquid Sheet ◽  
Diagnostic Methods ◽  
Number Density ◽  
Spray Structure ◽  
Optical Diagnostic ◽  
Size Number ◽  
Optimum Arrangement ◽  
Fuel Nozzle

In gas turbine combustors, optimum arrangement between a fuel nozzle and a swirler/prefilmer module must be sought to achieve satisfactory ignition and stability characteristics in addition to reduced level of emissions. However, due to thermal expansion of the combustor or misalignment of the fuel nozzle, the location of a fuel nozzle may vary. Displacement of a fuel nozzle may change the amount of fuel injected to the pre-filming device (usually the inner swirler wall) and the location of attachment, which in turn affects the thickness of pre-filming liquid sheet on the wall. As a result, the spray structure formed by pre-filming airblast atomization may be significantly changed. An experimental investigation is carried out to study the effects of fuel nozzle displacement on the structure of a spray formed by a dual orifice pressure atomizer and a counter-rotating dual swirler. The inner wall of the swirler is designed to be used as a pre-filming device. The behavior of droplets, the flow characteristics of the swirling air flow, and the interaction between droplets and the flow are studied. Optical diagnostic methods including a flow visualization and an Adaptive Phase/Doppler technique are used. Distributions of droplet size, number density, and liquid phase volume flux are presented for various fuel nozzle displacements, in addition to gas phase velocity.

Time resolved optical diagnostic methods for electric gun systems

1991 ◽  
Vol 27 (1) ◽  
pp. 143-146 ◽  
Author(s):  
T. Karasinski ◽  
K.P. Zocha ◽  
C.D. Zwingel
Keyword(s):  
Diagnostic Methods ◽  
Time Resolved ◽  
Optical Diagnostic

scholarly journals Effect of Ti(C, N) Particle on the Impact Toughness of B-Microalloyed Steel

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 868 ◽  
Author(s):  
Yu Huang ◽  
Guo-Guang Cheng ◽  
Shi-Jian Li ◽  
Wei-Xing Dai ◽  
You Xie
Keyword(s):  
Impact Toughness ◽  
Microalloyed Steel ◽  
Fracture Initiation ◽  
Sem Analysis ◽  
Number Density ◽  
Size Number ◽  
Microalloying Elements ◽  
The Impact ◽  
Ti Content ◽  
Scanning Electron

Simultaneously improving the toughness and strength of B-microalloyed steel by adding microalloying elements (Nb, V, Ti) has been an extensively usedmethod for researchers. However, coarse Ti(C, N) particle will precipitate during solidification with inappropriate Ti content addition, resulting in poor impact toughness. The effect of the size, number density, and location of Ti(C, N) particle on the impact toughness of B-microalloyed steel with various Ti/N ratios was investigated. Coarse Ti(C, N) particles were investigated to act as the cleavage fracture initiation sites, by using scanning electron microscopy (SEM) analysis. When more coarse Ti(C, N) inclusions were located in ferrite instead of pearlite, the impact toughness of steel with ferrite–pearlite microstructure was lower. Meanwhile, when the size or the number density of Ti(C, N) inclusions was larger, the impact toughness was adversely affected. Normalizing treatment helps to improve the impact property of B-microalloyed steel, owing to the location of Ti(C, N) particles being partly changed from ferrite to pearlite. The formation mechanism of coarse Ti(C, N) particles was calculated by the thermodynamic software Factsage 7.1 and Thermo-Calc. The Ti(C, N) particles formed during the solidification of molten steel, and the N-rich Ti(C, N) phase precipitated first and, then, followed by the C-rich Ti(C, N) phase. Decreasing the Ti and N content is an effective way to inhibit the formation of coarse Ti(C, N) inclusions.

scholarly journals Monte Carlo simulation for soot dynamics

2012 ◽  
Vol 16 (5) ◽  
pp. 1391-1394 ◽  
Author(s):  
Kun Zhou
Keyword(s):  
Particle Size ◽  
Monte Carlo ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Gas Phase ◽  
Volume Fraction ◽  
Soot Formation ◽  
Bimodal Distribution ◽  
Number Density ◽  
Stochastic Error

A new Monte Carlo method termed Comb-like frame Monte Carlo is developed to simulate the soot dynamics. Detailed stochastic error analysis is provided. Comb-like frame Monte Carlo is coupled with the gas phase solver Chemkin II to simulate soot formation in a 1-D premixed burner stabilized flame. The simulated soot number density, volume fraction, and particle size distribution all agree well with the measurement available in literature. The origin of the bimodal distribution of particle size distribution is revealed with quantitative proof.

An Experimental Study on Modeling of Fuel Atomization for Simulating the Idle Regime of a Gas Turbine Combustor by Atmospheric Testing

1997 ◽  
Author(s):  
Yeoung Min Han ◽  
Min Soo Yoon ◽  
Woo Seok Seol ◽  
Dae Sung Lee ◽  
Victor I. Yagodkin ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Diagnostic Methods ◽  
Fuel Spray ◽  
Main Stage ◽  
Gas Turbine Combustor ◽  
Spray Characteristics ◽  
Fuel Atomization ◽  
Fuel Nozzle ◽  
Loading Parameter ◽  
The Cost

An experimental investigation is carried out on modeling of fuel atomization for the purpose of simulating the idle regime of a gas turbine combustor through atmospheric testing. If the simulation is successfully applied, it will significantly reduce the cost of testing. The simulation must sustain nearly the same fuel spray characteristics and the same aerodynamics at the exit of the frontal device. Air assisting through the main stage of a dual orifice fuel nozzle is employed to match the fuel spray characteristics. Optical diagnostic methods including flow visualization and Adaptive Phase/Doppler Velocimetry are used for the investigation of spray characteristics. Once the fuel spray characteristics are matched by air assisting, the combustor characteristics may then be matched by maintaining the loading parameter constant. The possibility of modeling with air assisting is shown and appropriate conditions for air assisting are found.

scholarly journals Inclusion Characteristics in 95CrMo Steels with Different Calcium and Sulfur Contents

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 619 ◽  
Author(s):  
Xiang Li ◽  
Xiao Long ◽  
Linzhu Wang ◽  
Shouhao Tong ◽  
Xiutao Wang ◽  
...  
Keyword(s):  
Outer Layer ◽  
Three Dimensional ◽  
Average Diameter ◽  
Inclusion Size ◽  
Number Density ◽  
Cooling Process ◽  
Oxide Inclusions ◽  
Industrial Experiments ◽  
Size Number

In order to study the effect of Ca and sulfur contents on the characteristics of inclusions, industrial experiments using 95CrMo steel were conducted. SEM-EDS detections and stereological analysis were used to probe the characteristics of inclusions, including their compositions, morphologies, size, number density, and distribution. The results indicate that there were mainly three types of inclusions in 95CrMo steel billets with 6–18 ppm Ca and 30–100 ppm S: inclusions with single-phased morphology mainly composed of oxides; isolated MnS/CaS-only inclusions; inclusions with multi-phased morphology. The three-dimensional inclusion size distribution suggests that there were more Type-1 inclusions with a small size in low S containing steels. The average diameter of all types of inclusions increased with increasing Ca or S content in 95CrMo steel, indicating that the formation of MnS and CaS coarsened their size. The density distribution of inclusions indicates that the more inclusions there are, the more easily they aggregate and collide. Moreover, it is presumably concluded that the formation of sulfide in the outer layer of oxide inclusions weaken the attraction between oxide inclusions. The equilibrated transformation and formation of inclusions during the cooling process of 95CrMo steel was discussed based on thermodynamic calculation. The equilibrated transformation trajectory of inclusions in 95CrMo steel during the cooling process was Ca2SiO4 + MgO → Ca3MgSi2O8 → Spinel + CaS, which was corresponding to the detected results. The precipitation regular of sulfide was obtained. The formation mechanism for three types of inclusions was discussed.

Investigation of Diagnostic Methods of Electron Number Density in Laser Plasma

2013 ◽  
Vol 437 ◽  
pp. 761-764
Author(s):  
Lan Li ◽  
Qian Li ◽  
Yong Li
Keyword(s):  
Laser Plasma ◽  
Emission Spectroscopy ◽  
Optical Emission Spectroscopy ◽  
Spatial Information ◽  
Optical Emission ◽  
Diagnostic Methods ◽  
Number Density ◽  
Basic Principles ◽  
Applicable Range ◽  
Temporal And Spatial

Langmuir probe, interferometry/reflectometry and optical emission spectroscopy, diagnostic methods in common use for plasma, were analyzed. Basic principles, system compositions and applicable range were compared with each other. Optical emission spectroscopy method is easy to obtain temporal and spatial information and has large measuring range, which is more suitable for diagnosis for laser plasma.

scholarly journals Gas-Phase Silicon Atom Densities in the Chemical Vapor Deposition of Silicon from Silane

1993 ◽  
Vol 334 ◽  
Author(s):  
Michael E. Coltrin ◽  
William G. Breiland ◽  
Pauline Ho
Keyword(s):  
Chemical Vapor Deposition ◽  
Gas Phase ◽  
Silicon Atom ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Rotating Disk ◽  
Number Density ◽  
Atom Number ◽  
Density Profiles ◽  
Calculated Density

AbstractSilicon atom number density profiles have been measured using laser-induced fluorescence during the chemical vapor deposition of silicon from silane. Measurements were obtained in a rotating-disk reactor as a function of silane partial pressure and the amount of hydrogen added to the carrier gas. Absolute number densities were obtained using an atomic absorption technique. Results were compared with calculated density profiles from a model of the coupled fluid flow, gas-phase and surface chemistry for an infinite-radius rotating disk. An analysis of the reaction mechanism showed that the unimolecular decomposition of SiH2 is not the dominant source of Si atoms. Profile shapes and positions, and all experimental trends are well matched by the calculations. However, the calculated number density is up to 100 times smaller than measured.

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