scholarly journals Flame stability and behavior inside meso-scale combustor with different flame holder

2018 ◽  
Vol 159 ◽  
pp. 02011
Author(s):  
Lilis Yuliati
Keyword(s):  
Flat Plate ◽  
Cross Section ◽  
Wire Mesh ◽  
Flame Stability ◽  
Flame Holder ◽  
Circular Holes ◽  
Stable Flame ◽  
And Behavior ◽  
Reactant Distribution ◽  
Meso Scale

Flame stability and behavior inside meso-scale combustor with different flame holder was investigated experimentally. Three types of flame holder i.e. wire mesh, flat plate with circular holes and flat plate with narrow slits, were used to improve the flame stability inside the meso-scale combustor. Combustor with flat plate - narrow slits flame holder has the best flame stability, i.e. stable flame established inside the combustor at the highest reactant velocity compared to the other combustor with the different flame holder. Furthermore, combustor with wire mesh and flat plate with narrow slits have a relatively uniform flame colour at the combustor cross section, compared to flame visualization inside meso-scale combustor with flame holder of flat plate with circular holes. This phenomena is related to non-uniform reactant distribution on the combustor cross section.

Flame Stability of Gaseous Fuel Combustion inside Meso-Scale Combustor with Double Wire Mesh

2014 ◽  
Vol 664 ◽  
pp. 231-235
Author(s):  
Lilis Yuliati
Keyword(s):  
Flow Rate ◽  
Equivalence Ratio ◽  
Fuel Mixture ◽  
Wire Mesh ◽  
Gaseous Fuel ◽  
Flame Stability ◽  
Wire Meshes ◽  
Reactant Flow ◽  
Stability Area ◽  
Meso Scale

Flame stability of gaseous fuel inside meso-scale combustor with double wire mesh was investigated experimentally. Combustor was made from quartz glass tube with an inner diameter of 3,5 mm and an outer diameter of 5 mm. Two pieces of wire meshes were made from stainless steel inserted at 10 and 13 mm from the end of combustor. Propane was used as fuel in this research. Flame was stabilized in the region between two wire meshes. The flame has a blue luminosity, indicate no soot formation condition. However, the second wire mesh and combustor wall has red luminousity at high velocity reactant, indicate that they have high temperature and emmited heat radiation. Meso-scale combustor with double wire mesh has broader flame stability area if compared to combustor with single wire mesh. Extention of this region occured toward lower equivalence ratio for lean fuel mixture, as well as toward higher equivalence ratio for rich fuel mixture. The most important extention region of flame stability area is toward higher reactant flow rate. It was caused by existing of second wire mesh which has function to prevent occurence of blow–off at relatively high reactant flow rate, as well as to increase heat recirculation to unburnt reactant as a results of higher wall temperature.

Flammability Limit and Flame Visualization of Gaseous Fuel Combustion Inside Meso-scale Combustor with Different Thermal Conductivity

2014 ◽  
Vol 493 ◽  
pp. 204-209 ◽  
Author(s):  
Lilis Yuliati ◽  
Mega Nur Sasongko ◽  
Slamet Wahyudi
Keyword(s):  
Thermal Conductivity ◽  
Wire Mesh ◽  
Gaseous Fuel ◽  
Flammability Limit ◽  
Rich Mixture ◽  
Flame Holder ◽  
Cross Section Area ◽  
Section Area ◽  
Liquid Petroleum Gas ◽  
Meso Scale

This study experimentally investigated effect of thermal conductivity on the combustioncharacteristics of gaseous fuel inside a meso-scale combustor. Combustion characteristics that wereobserved in this research include flame visualization and flammability limit. Quartz glass, stainlesssteel and copper tubes with inner diameters of 3.5 mm were used as combustors. Stainless steel wiremesh was inserted inside meso-scale combustor as a flame holder. Liquid petroleum gas (LPG),which is common fuel use by Indonesian people, was used as a gaseous fuel. A stable blue flame wasestablished inside meso-scale combustor at the downstream of wire mesh for all combustor withdifferent thermal conductivity. Furthermore, flame color is blue for combustion of fuel lean orstoichiometric mixture, and blue-green for combustion of fuel rich mixture. Meso-scale combustorwith the highest thermal conductivity has the narrowest flame cross section area, especially at lowerreactant velocity. Vice versa, this combustor has the widest flammability limit, mainly at the higherreactant velocity.

Flame Stability Measurement on Rectangular Slot Meso-Scale Combustor

2016 ◽  
Vol 836 ◽  
pp. 271-276 ◽  
Author(s):  
Satworo Adiwidodo ◽  
I.N.G. Wardana ◽  
Lilis Yuliati ◽  
Mega Nur Sasongko
Keyword(s):  
Heat Loss ◽  
Dead Zone ◽  
Flame Temperature ◽  
Flame Stabilization ◽  
Flame Stability ◽  
Flammability Limit ◽  
Rectangular Slot ◽  
Stability Measurement ◽  
Stable Flame ◽  
Meso Scale

The biggest problem of combustion in the micro-scale or meso-scale combustor is heat loss. Heat loss led to a difficult of stable flame. This research aims to elucidate the flame stabilization and flammability limit of LPG-oxygen premixed flame, temperature distribution and flame visualization. Flame stabilization and flammability limit map are shows in φ - U plane. The result shows that there are six regions in the map that is stable without noise, stable with noise, transition zone, dead zone, pseudo stable, and blow off. Measurement parameters are LPG-oxygen flow velocity at various equivalent ratio and temperature. The flame stabilization and flammability limit map within measurement parameters are discussed.

Formation of defects in implanted hipox-structures

1992 ◽  
Vol 50 (2) ◽  
pp. 1406-1407
Author(s):  
Peter Pegler ◽  
N. David Theodore ◽  
Ming Pan
Keyword(s):  
High Pressure ◽  
Cross Section ◽  
Semiconductor Devices ◽  
Silicon Substrates ◽  
Processing Conditions ◽  
Pressure Oxidation ◽  
Deep Trench ◽  
Local Oxidation ◽  
Trench Isolation ◽  
And Behavior

High-pressure oxidation of silicon (HIPOX) is one of various techniques used for electrical-isolation of semiconductor-devices on silicon substrates. Other techniques have included local-oxidation of silicon (LOCOS), poly-buffered LOCOS, deep-trench isolation and separation of silicon by implanted oxygen (SIMOX). Reliable use of HIPOX for device-isolation requires an understanding of the behavior of the materials and structures being used and their interactions under different processing conditions. The effect of HIPOX-related stresses in the structures is of interest because structuraldefects, if formed, could electrically degrade devices.This investigation was performed to study the origin and behavior of defects in recessed HIPOX (RHIPOX) structures. The structures were exposed to a boron implant. Samples consisted of (i) RHlPOX'ed strip exposed to a boron implant, (ii) recessed strip prior to HIPOX, but exposed to a boron implant, (iii) test-pad prior to HIPOX, (iv) HIPOX'ed region away from R-HIPOX edge. Cross-section TEM specimens were prepared in the <110> substrate-geometry.

Influence of the Side Walls on the Turbulent Center-Plane Boundary-Layer in a Square Duct

1978 ◽  
Vol 100 (1) ◽  
pp. 91-96 ◽  
Author(s):  
V. de Brederode ◽  
P. Bradshaw
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Flat Plate ◽  
Cross Section ◽  
Secondary Flows ◽  
Plane Boundary ◽  
Square Duct ◽  
Streamwise Pressure Gradient ◽  
Side Walls ◽  
Working Section

Measurements in the entry region of a square duct (specifically, a wind-tunnel working section) show that the direct effect of stress-induced secondary flows in the corners on the center-plane boundary layer is negligible for boundary layers thinner than about one-fourth of the duct width. Further, the effects of streamwise pressure gradient and of quasi-collinear lateral convergence tend to cancel so that the velocity profiles and skin friction are quite close to those on a flat plate. This shows that the boundary layer on the floor of a wind tunnel of constant, square cross section can be used to simulate a flat-plate flow even when the boundary layer thickness is as large as one-fourth of the tunnel height.

An experimental investigation of resonant interaction of a rectangular jet with a flat plate

2015 ◽  
Vol 779 ◽  
pp. 751-775 ◽  
Author(s):  
K. B. M. Q. Zaman ◽  
A. F. Fagan ◽  
J. E. Bridges ◽  
C. A. Brown
Keyword(s):  
Mach Number ◽  
Flat Plate ◽  
Cross Section ◽  
Leading Edge ◽  
Resonant Interaction ◽  
Trailing Edge ◽  
Resonant Condition ◽  
Direction Parallel ◽  
Rectangular Jet ◽  
Axis Switching

The interaction between an 8:1 aspect ratio rectangular jet and a flat plate, placed parallel to the jet, is addressed in this study. At high subsonic conditions and for certain relative locations of the plate, a resonance takes place with accompanying audible tones. Even when the tone is not audible the sound pressure level spectra are often marked by conspicuous peaks. The frequencies of these peaks, as functions of the plate’s length, its location relative to the jet as well as jet Mach number, are studied in an effort to understand the flow mechanism. It is demonstrated that the tones are not due to a simple feedback between the nozzle exit and the plate’s trailing edge; the leading edge also comes into play in determining the frequency. With parametric variation, it is found that there is an order in the most energetic spectral peaks; their frequencies cluster in distinct bands. The lowest frequency band is explained by an acoustic feedback involving diffraction at the plate’s leading edge. Under the resonant condition, a periodic flapping motion of the jet column is seen when viewed in a direction parallel to the plate. Phase-averaged Mach number data on a cross-stream plane near the plate’s trailing edge illustrate that the jet cross-section goes through large contortions within the period of the tone. Farther downstream a clear ‘axis switching’ takes place for the time-averaged cross-section of the jet that does not occur otherwise for a non-resonant condition.

scholarly journals Effect of wire mesh on the heat transfer from a flat plate under free water jet impingement quenching

2018 ◽  
Vol 57 (4) ◽  
pp. 3841-3850
Author(s):  
H.A. Abotaleb ◽  
M.Y. Abdelsalam ◽  
M.M. Aboelnasr
Keyword(s):  
Heat Transfer ◽  
Flat Plate ◽  
Free Water ◽  
Jet Impingement ◽  
Water Jet ◽  
Wire Mesh

Experimental Investigation of Size Effects of FCC Polycrystal by Shear Banding

1999 ◽  
Vol 121 (2) ◽  
pp. 156-161
Author(s):  
Osamu Watanabe ◽  
Takayuki Kurata
Keyword(s):  
Size Effect ◽  
Cross Section ◽  
Size Effects ◽  
Rectangular Cross Section ◽  
Pure Aluminum ◽  
Shear Banding ◽  
Compressive Loading ◽  
Thickness Effect ◽  
Internal Mechanism ◽  
Meso Scale

Several plasticity phenomena display a size effect where the smaller the size is the stronger its response. This effect relates to the plastic gradients, appearing in plastically inhomogeneous material. The present paper describes results of an experimental meso-scale study using the specimens having rectangular cross section made of FCC polycrystal of pure Aluminum and OFHC Copper under the tensile or compressive loading. Experimental measurements are carried out to investigate thickness effect and grain size effect in connection with size effect, and the internal mechanism of plastic flow in the specimens is also discussed.

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