Combustion Characteristics for Turbulent Prevaporized Premixed Flame Using Commercial Light Diesel and Kerosene Fuels

Experimental study has been carried out for investigating fuel type, fuel blends, equivalence ratio, Reynolds number, inlet mixture temperature, and holes diameter of perforated plate affecting combustion process for turbulent prevaporized premixed air flames for different operating conditions. CO2, CO, H2, N2, C3H8, C2H6, C2H4, flame temperature, and gas flow velocity are measured along flame axis for different operating conditions. Gas chromatographic (GC) and CO/CO2infrared gas analyzer are used for measuring different species. Temperature is measured using thermocouple technique. Gas flow velocity is measured using pitot tube technique. The effect of kerosene percentage on concentration, flame temperature, and gas flow velocity is not linearly dependent. Correlations for adiabatic flame temperature for diesel and kerosene-air flames are obtained as function of mixture strength, fuel type, and inlet mixture temperature. Effect of equivalence ratio on combustion process for light diesel-air flame is greater than for kerosene-air flame. Flame temperature increases with increased Reynolds number for different operating conditions. Effect of Reynolds number on combustion process for light diesel flame is greater than for kerosene flame and also for rich flame is greater than for lean flame. The present work contributes to design and development of lean prevaporized premixed (LPP) gas turbine combustors.

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The Features of Measuring the Gas Flow Velocity in Pipes by an Ultrasonic Correlation Method

Acoustical Physics ◽

10.1134/s1063771021020044 ◽

2021 ◽

Vol 67 (2) ◽

pp. 216-221

Author(s):

A. D. Mansfeld ◽

G. P. Volkov ◽

R. V. Belyaev ◽

A. G. Sanin ◽

P. R. Gromov ◽

...

Keyword(s):

Flow Velocity ◽

Gas Flow ◽

Correlation Method ◽

Gas Flow Velocity

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METHODS OF MAINTAINING THE PROJECT LEVELS OF GAS PRODUCTION AT THE FINAL STAGE OF DEVELOPMENT OF DEPOSITS

Oil and Gas Studies ◽

10.31660/0445-0108-2017-4-80-83 ◽

2017 ◽

pp. 80-83

Author(s):

E. V. Panikarovskii ◽

V. V. Panikarovskii

Keyword(s):

Flow Velocity ◽

Final Stage ◽

Gas Flow ◽

Gas Production ◽

Stage Of Development ◽

Surfactant Solutions ◽

Gas Flow Velocity

In the case of self-kill of wells, the gas flow velocity in the lifting column is not sufficient for carrying to the surface of the liquid, accumulated in the wellbore. To remove liquid from the bottom of wells, solid and liquid surfactants are used. As a result of conducted studies of surfactant compositions, the components of surfactant solutions were chosen to remove liquid from the bottom of wells.

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Effects of Shield Gas Flow on Meltpool Variability and Signature in Scanned Laser Melting

Volume 1: Additive Manufacturing; Advanced Materials Manufacturing; Biomanufacturing; Life Cycle Engineering; Manufacturing Equipment and Automation ◽

10.1115/msec2020-8410 ◽

2020 ◽

Author(s):

David C. Deisenroth ◽

Jorge Neira ◽

Jordan Weaver ◽

Ho Yeung

Keyword(s):

Additive Manufacturing ◽

Aspect Ratio ◽

Flow Velocity ◽

Process Monitoring ◽

Gas Flow ◽

Laser Energy ◽

Flow Speed ◽

Powder Bed ◽

Flow Speeds ◽

Gas Flow Velocity

Abstract In laser powder bed fusion metal additive manufacturing, insufficient shield gas flow allows accumulation of condensate and ejecta above the build plane and in the beam path. These process byproducts are associated with beam obstruction, attenuation, and thermal lensing, which then lead to lack of fusion and other defects. Furthermore, lack of gas flow can allow excessive amounts of ejecta to redeposit onto the build surface or powder bed, causing further part defects. The current investigation was a preliminary study on how gas flow velocity and direction affect laser delivery to a bare substrate of Nickel Alloy 625 (IN625) in the National Institute of Standards and Technology (NIST) Additive Manufacturing Metrology Testbed (AMMT). Melt tracks were formed under several gas flow speeds, gas flow directions, and energy densities. The tracks were then cross-sectioned and measured. The melt track aspect ratio and aspect ratio coefficient of variation (CV) were reported as a function of gas flow speed and direction. It was found that a mean gas flow velocity of 6.7 m/s from a nozzle 6.35 mm in diameter was sufficient to reduce meltpool aspect ratio CV to less than 15 %. Real-time inline hotspot area and its CV were evaluated as a process monitoring signature for identifying poor laser delivery due to inadequate gas flow. It was found that inline hotspot size could be used to distinguish between conduction mode and transition mode processes, but became diminishingly sensitive as applied laser energy density increased toward keyhole mode. Increased hotspot size CV (associated with inadequate gas flow) was associated with an increased meltpool aspect ratio CV. Finally, it was found that use of the inline hotspot CV showed a bias toward higher CV values when the laser was scanned nominally toward the gas flow, which indicates that this bias must be considered in order to use hotspot area CV as a process monitoring signature. This study concludes that gas flow speed and direction have important ramifications for both laser delivery and process monitoring.

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Research on the Influence of Furnace Structure on Copper Cooling Stave Life

High Temperature Materials and Processes ◽

10.1515/htmp-2017-0040 ◽

2019 ◽

Vol 38 (2019) ◽

pp. 1-7

Author(s):

Feng-guang Li ◽

Jian-liang Zhang

Keyword(s):

Service Life ◽

Flow Velocity ◽

Gas Flow ◽

Flow Distribution ◽

Distribution Model ◽

Variational Structure ◽

Shaft Angle ◽

The Stability ◽

Gas Flow Velocity ◽

Copper Stave

AbstractIn this paper, a blast furnace gas flow distribution model with variable furnace structure was founded based on CFD (computational fluid dynamics) theory, and the gas velocity distribution near the surface of the copper staves in different areas of the BF is calculated under different conditions of variational structure parameters like Bosh angle, shaft angle, and the newly proposed “equivalent Bosh angle.” Based on the calculation, the influence rule of the BF structure on the service life of copper stave and the corresponding operation measures were obtained. The result shows that the increase of the Bosh angle and the decrease of the shaft angle will incur increasing of the gas flow velocity near the surface of the copper staves, which is harmful to the cooling stave life; the variation of the equivalent Bosh angle has a most significant influence on the cooling stave life, and the increase of the equivalent Bosh angle will cause a sharp increase of the gas flow velocity, which will damage the copper staves seriously; adopting long tuyeres and minishing the equivalent Bosh angle will reduce the washing action of the gas flow and ensure the stability of slag hanging to achieve a long service life of copper staves.

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Experimental Study of Vortex Shedding From a Solid Sphere in Turbulent Freestream

Volume 1: Symposia, Parts A and B ◽

10.1115/fedsm2005-77168 ◽

2005 ◽

Cited By ~ 2

Author(s):

Himanshu Tyagi ◽

Rui Liu ◽

David S.-K. Ting ◽

Clifton R. Johnston

Keyword(s):

Experimental Study ◽

Reynolds Number ◽

Flow Velocity ◽

Vortex Shedding ◽

Isotropic Turbulence ◽

Vortex Formation ◽

Perforated Plate ◽

Solid Sphere ◽

Mean Flow ◽

Static Pressure Distribution

The study of vortex shedding from a sphere assumes an important role because of its relevance to numerous aerodynamic and hydrodynamic applications. Parameters such as coefficient of drag and static pressure distribution are largely influenced by vortex shedding, and it is found by past studies that the freestream turbulence can interact and alter the vortex formation and shedding drastically. Most of these studies, however, were conducted in the low Reynolds number regime and the vortex shedding results had been described only qualitatively. To better understand the aerodynamics of a sphere in turbulent flow, an experimental study was initiated in a low speed wind tunnel to quantify the vortex shedding characteristics. The Reynolds number of the flow, based on the diameter of the sphere (d), was set at 3.3 × 104, 5 × 104 and 6.6 × 104 by varying the mean flow velocity. The sphere was placed at 20D (= 7.5d) downstream from a perforated plate, where D = 37.5 mm is the size of the holes in the perforated plate, uniquely designed for generating near-isotropic turbulence. Hot-wire measurements were taken at 10D (= 3.75d), 20D (= 7.5d) and 30D (= 11.25d) downstream of the sphere in absence and presence of the perforated plate. The vortex shedding frequency was deduced from the instantaneous flow velocity data.

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