Experimental study, 1D volume-averaged calculations and 3D direct pore level simulations of the flame stabilization in porous inert media at elevated pressure

Combustion using silicon carbide coated, carbon-carbon composite porous inert media (PIM) was investigated. Two combustion modes, surface and interior, depending upon the location of flame stabilization, were considered. Combustion performance was evaluated by measurements of pressure drop across the PIM, emissions of NOx and CO, and the lean blow-off limit. Data were obtained for the two combustion modes at identical conditions for a range of reactant flowrates, equivalence ratios, and pore sizes of the PIM. Results affirm PIM combustion as an effective method to extend the blow-off limit in lean premixed combustion.

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Experimental Study of Surface and Interior Combustion Using Composite Porous Inert Media

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.1789516 ◽

2005 ◽

Vol 127 (2) ◽

pp. 307-313 ◽

Cited By ~ 37

Author(s):

T. L. Marbach ◽

A. K. Agrawal

Keyword(s):

Experimental Study ◽

Silicon Carbide ◽

Pressure Drop ◽

Carbon Composite ◽

Flame Stabilization ◽

Premixed Combustion ◽

Lean Premixed Combustion ◽

Combustion Modes ◽

Porous Inert Media ◽

Coated Carbon

Combustion using silicon carbide coated, carbon–carbon composite porous inert media (PIM) was investigated. Two combustion modes, surface and interior, depending upon the location of flame stabilization, were considered. Combustion performance was evaluated by measurements of pressure drop across the PIM, emissions of NOx and CO, and the lean blow-off limit. Data were obtained for the two combustion modes at identical conditions for a range of reactant flowrates, equivalence ratios, and pore sizes of the PIM. Results affirm PIM combustion as an effective method to extend the blow-off limit in lean premixed combustion.

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Experimental Study on the Influence of Pressure on the Flame Stabilization in Porous Inert Media (PIM)

Volume 2: Combustion, Fuels and Emissions, Parts A and B ◽

10.1115/gt2012-68234 ◽

2012 ◽

Cited By ~ 1

Author(s):

Cesar Bedoya ◽

Peter Habisreuther ◽

Nikolaos Zarzalis ◽

Chockalingam Prathap ◽

Hadi Ebrahimi

Keyword(s):

Burning Velocity ◽

Thermal Power ◽

Elevated Pressure ◽

Flame Stabilization ◽

Operating Conditions ◽

Combustion Stability ◽

Pollutant Emissions ◽

Lean Mixture ◽

Wide Range ◽

Porous Inert Media

Porous burners offer a possible solution to attain higher combustion stability under premixed conditions with ultra low pollutant emissions. To analyze the feasibility of PIM (porous inert media) in energy conversion processes, studies at elevated pressure have been carried out. In the present work, burning velocity of natural gas-air mixtures for lean mixture conditions at elevated pressure is obtained in a conical PIM by determining the flame location using thermocouples. Pressure, thermal power, equivalence ratio and initial temperature were varied in order to study their effect on the flame stability. The pressure was varied from 1.1 to 14.0 bar, and initial temperatures from 300 to 400K. The burning velocity data obtained from present measurements show good agreement with literature data at atmospheric pressure. The results show that the burning velocities measured in PIM decreased non-linearly with increase in pressure. Also, the decrease in the burning velocity in the PIM with pressure is more pronounced for lean mixture conditions. Present results indicate that the PIM produces stable flames for a wide range of operating conditions and generate low pollutant emissions, which show that it is a potential alternative for conventional burners.

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Factors Contributing to Increased Blast Overpressure Inside Modern Ballistic Helmets

Applied Sciences ◽

10.3390/app10207193 ◽

2020 ◽

Vol 10 (20) ◽

pp. 7193

Author(s):

Maciej Skotak ◽

Jonathan Salib ◽

Anthony Misistia ◽

Arturo Cardenas ◽

Eren Alay ◽

...

Keyword(s):

Experimental Study ◽

Shock Tube ◽

Principle Component Analysis ◽

Hot Spots ◽

Shape Factor ◽

Elevated Pressure ◽

Focal Points ◽

Parietal Region ◽

Blast Overpressure ◽

Pressure Fields

This study demonstrates the orientation and the "shape factor" have pronounced effects on the development of the localized pressure fields inside of the helmet. We used anatomically accurate headform to evaluate four modern combat helmets under blast loading conditions in the shock tube. The Advanced Combat Helmet (ACH) is used to capture the effect of the orientation on pressure under the helmet. The three modern combat helmets: Enhanced Combat Helmet (ECH), Ops-Core, and Airframe, were tested in frontal orientation to determine the effect of helmet geometry. Using the unhelmeted headform data as a reference, we characterized pressure distribution inside each helmet and identified pressure focal points. The nature of these localized “hot spots” is different than the elevated pressure in the parietal region of the headform under the helmet widely recognized as the under-wash effect also observed in our tests. It is the first experimental study which indicates that the helmet presence increased the pressure experienced by the eyes and the forehead (glabella). Pressure fingerprinting using an array of sensors combined with the application of principle component analysis (PCA) helped elucidate the subtle differences between helmets.

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