Determination of normal flame velocity and critical diameter of flame extinction in ammonia-air mixture

1978 ◽  
Vol 14 (6) ◽  
pp. 710-713 ◽  
Author(s):  
V. F. Zakaznov ◽  
L. A. Kursheva ◽  
Z. I. Fedina
Keyword(s):  
Critical Diameter ◽  
Flame Velocity ◽  
Flame Extinction ◽  
Normal Flame ◽  
Normal Flame Velocity

Normal flame velocity of propane-and-air mixtures at high pressures and temperatures

1989 ◽  
Vol 25 (1) ◽  
pp. 52-57 ◽  
Author(s):  
V. S. Babkin ◽  
V. N. Bukharov ◽  
V. V. Mol'kov
Keyword(s):  
High Pressures ◽  
Flame Velocity ◽  
High Pressures And Temperatures ◽  
Normal Flame ◽  
Normal Flame Velocity

Effect of pressure on normal flame velocity investigated by the initial-section method in a constant-volume vessel

1969 ◽  
Vol 2 (2) ◽  
pp. 32-37 ◽  
Author(s):  
V. S. Babkin ◽  
A. V. V'yun ◽  
L. S. Kozachenko
Keyword(s):  
Initial Section ◽  
Constant Volume ◽  
Flame Velocity ◽  
Section Method ◽  
Effect Of Pressure ◽  
Normal Flame ◽  
Normal Flame Velocity

Equations for determining normal flame velocity in a constant-volume spherical bomb

1969 ◽  
Vol 3 (2) ◽  
pp. 168-171 ◽  
Author(s):  
V. S. Babkin ◽  
Yu. G. Kononenko
Keyword(s):  
Constant Volume ◽  
Flame Velocity ◽  
Normal Flame ◽  
Normal Flame Velocity

The Normal Flame Velocity and Analysis of the Effect of the System Parameters on This Velocity

2005 ◽  
Vol 43 (6) ◽  
pp. 937-946 ◽  
Author(s):  
Yu. V. Polezhaev ◽  
I. L. Mostinskii
Keyword(s):  
Flame Velocity ◽  
System Parameters ◽  
Normal Flame ◽  
Normal Flame Velocity

Determination of Intrinsic Magnetic Parameters of SmCo5 Phase in Sintered Samples

2005 ◽  
Vol 498-499 ◽  
pp. 129-133 ◽  
Author(s):  
Marcos Flavio de Campos ◽  
Fernando José Gomes Landgraf
Keyword(s):  
Powder Metallurgy ◽  
Domain Wall ◽  
Kerr Effect ◽  
Critical Diameter ◽  
Optical Microscope ◽  
Domain Theory ◽  
Magnetic Domains ◽  
Magnetic Parameters ◽  
Intrinsic Parameters

SmCo5 magnets are usually produced by powder metallurgy route, including milling, compaction and orientation under magnetic field, sintering and heat treatment. The samples produced by powder metallurgy, with grain size around 10 μm, are ideal for determination of intrinsic parameters. The first step for determination of intrinsic magnetic parameters is obtaining images of domain structure in demagnetized samples. In the present study, the domain images were produced by means of Kerr effect, in a optical microscope. After the test of several etchings, Nital appears as the most appropriate for observation of magnetic domains by Kerr effect. Applying Stereology and Domain Theory, several intrinsic parameters of SmCo5 phase were determined: domain wall energy 120 erg/cm2, critical diameter for single domain particle size 2 μm and domain wall thickness 60 Å. In the case of SmCo5, and also other phases with high magnetocrystalline anisotropy, Domain Theory presents several advantages when compared with Micromagnetics.

Optical Characterization and Defect inspection for 3D stacked IC technology

2014 ◽  
Vol 2014 (1) ◽  
pp. 000630-000634 ◽  
Author(s):  
Gilles Fresquet ◽  
Jean-Philippe Piel
Keyword(s):  
Optical Sensors ◽  
Silicon Substrate ◽  
Critical Diameter ◽  
Back Side ◽  
Defect Inspection ◽  
Flexible Tool ◽  
Full Field ◽  
Silicon Thickness ◽  
Wafer Thinning

Advanced packaging technologies are rapidly evolving and 3D architectures requires new inspection and metrology techniques. Existing techniques need to be improved but new techniques must be developed to address new challenges induced by the last fabrication processes. To increase the development speed, it is a big advantage that metrology and defect inspection need to be present on the same platform and a flexible tool, with multi sensors, to be more versatile facing the different step of the process will be presented in this paper As 3D IC devices utilize TSVs for direct interconnect, the depth, top and bottom CD (critical diameter) of such TSVs with a diameter as small as 5 μm with a high aspect ratio is characterized. During wafer temporary bounding, which is an handling technique that allows wafer thinning with a thickness of less than 100 μm, by selecting the most sensitive sensor, determination of the thickness of each layer of the stack could be determined at the same time: silicon substrate, thin glue layer of few microns only and carrier which could be silicon or glass. After back-side processing and wafer thinning, the determination of the remaining silicon thickness (RST) below the TSV could be determined. Moreover back side roughness after grinding is also determined. After wafer thinning process, the TSVs are revealed at the back side of the wafer, leaving to appear copper pillars. The pillars height and co-planarity measurements are then addressed. Post CMP process control will be addressed by full field interferometry especially prior Copper to Copper direct bonding. Concerning the defect inspection, the NIR microscopy is used to control die to wafer stacking process, to reveal voids in the glue and cracks on the grinded silicon substrate. In this paper, we will present fast and nondestructive optical sensors based on low coherence infrared and white light interferometry and spectrometry techniques. These different sensors mounted on the same tool allow characterizing specifically and with an excellent sensitivity the different process steps described above. Concerning the defect inspections, techniques based on infrared microscopy and images techniques processing will be detailed and results will be presented to illustrate the possibilities of this inspection by microscopy.

Determination of the Critical Diameter of Explosive Materials

ARS Journal ◽  
1962 ◽  
Vol 32 (7) ◽  
pp. 1060-1065 ◽  
Author(s):  
IRVING JAFFE ◽  
DONNA PRICE
Keyword(s):  
Critical Diameter ◽  
Explosive Materials

scholarly journals Study of Experimental and Calculated Flame Speed of Methane/Oxygen-Enriched Flame in Gas Turbine Conditions As a Function of Water Dilution: Application to CO2 Capture by Membrane Processes

2017 ◽  
Author(s):  
G. Cabot ◽  
J. P. Chica Cano ◽  
S. de Persis ◽  
F. Foucher
Keyword(s):  
Reaction Mechanism ◽  
Gas Turbine ◽  
Co2 Capture ◽  
Methane Combustion ◽  
Steam Injection ◽  
Flame Velocity ◽  
Gas Turbine Cycle ◽  
Water Dilution ◽  
Numerical Approaches

A solution for CCS (Carbon Dioxide Capture and Sequestration of CO2) is oxycombustion. Due to the high cost of pure O2 production, however, other approaches recently emerged such as post-combustion coupled with Oxygen Enhanced Air (OEA). This is the solution studied in this paper, which presents an innovative gas turbine cycle, the Oxygen Enriched Air Steam Injection Gas Turbine Cycle (OEASTIG). The OEASTIG cycle is composed of Methane combustion with OEA (Oxygen Enhanced Air), EGR (Exhaust Gas Recirculation) and H2O coming from a STIG (Steam Injection Gas Turbine). CO2 capture is achieved by a membrane separator. The final aim of this work is to predict NO and CO emissions in the gas turbine by experimental and numerical approaches. Before carrying out this study, the validation of a reaction mechanism is mandatory. Moreover, this new gas turbine cycle impacts on the combustion zone and it is therefore necessary to understand the consequences of H2O and CO2 dilution on combustion parameters. While a large number of papers deal with CO2 dilution, only a few papers have investigated the impact of water dilution on methane combustion. A study of the influence of H2O dilution on the combustion parameters by experimental and numerical approaches was therefore carried out and is reported in the present paper. The paper is divided in three parts: i) description of the innovative gas turbine (OEASTIG) cycle and determination of the reactive mixtures compatible with its operation; ii) validation of the reaction mechanism by comparing laminar methane flame velocity measurements performed in a stainless steel spherical combustion chamber with calculations carried out in a freely propagating flame using the Chemical Workbench v.4.1. Package in conjunction with the GRIMech3.0 reaction mechanism; iii) Extrapolation to gas turbine conditions by prediction of flame velocities and determination of the feasible conditions from a gas turbine point of view (flame stability). In particular, mixtures (composed of CH4/O2/N2/H2O or CO2) leading to the same adiabatic temperature were investigated. Lastly, the influence of oxygen enrichment and H2O dilution (compared to CO2 dilution) were investigated.

Laminar Flame Velocity of Syngas Fuels

2010 ◽  
Author(s):  
Bidhan Dam ◽  
Vishwanath Ardha ◽  
Ahsan Choudhuri
Keyword(s):  
Laminar Flame ◽  
Burning Velocity ◽  
Flame Velocity ◽  
Laminar Burning Velocity ◽  
Velocity Data ◽  
Flame Propagation Velocity ◽  
Exit Velocity ◽  
Flat Flame ◽  
Burner Exit

The paper presents the experimental measurements of the laminar burning velocity of H2-CO mixtures. Hydrogen (H2) and carbon monoxide (CO) are the two primary constituents of syngas fuels. Three burner systems (nozzle, tubular, and flat flame) are used to quantify the effects of burner exit velocity profiles on the determination of laminar flame propagation velocity. The effects to N2 and CO2 diluents have been investigated as well, and it is observed that the effects of N2 and CO2 on the mixture burning velocity are significantly different. Finally, the burning velocity data of various syngas compositions (brown, bituminous, lignite and coke) are presented.

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