Combustion processes of hydrogen/oxygen diffusion flames under high-pressure conditions

1995 ◽  
Author(s):  
W Hsieh ◽  
A Yang
1981 ◽  
Vol 103 (1) ◽  
pp. 34-42 ◽  
Author(s):  
J. R. Shekleton

The Radial Engine Division of Solar Turbines International, an Operating Group of International Harvester, under contract to the U.S. Army Mobility Equipment Research & Development Command, developed and qualified a 10 kW gas turbine generator set. The very small size of the gas turbine created problems and, in the combustor, novel solutions were necessary. Differing types of fuel injectors, combustion chambers, and flame stabilizing methods were investigated. The arrangement chosen had a rotating cup fuel injector, in a can combustor, with conventional swirl flame stabilization but was devoid of the usual jet stirred recirculation. The use of centrifugal force to control combustion conferred substantial benefit (Rayleigh Instability Criteria). Three types of combustion processes were identified: stratified and unstratified charge (diffusion flames) and pre-mix. Emphasis is placed on five nondimensional groups (Richardson, Bagnold, Damko¨hler, Mach, and Reynolds numbers) for the better control of these combustion processes.


2014 ◽  
Vol 18 (6) ◽  
pp. 607-626 ◽  
Author(s):  
Jian Cai ◽  
Shenghui Lei ◽  
Adhiraj Dasgupta ◽  
Michael F. Modest ◽  
Daniel C. Haworth

Author(s):  
Snehaunshu Chowdhury ◽  
Razi Nalim ◽  
Thomas M. Sine

Emission controls in stationary gas engines have required significant modifications to the fuel injection and combustion processes. One approach has been the use of high-pressure fuel injection to improve fuel-air mixing. The objective of this study is to simulate numerically the injection of gaseous fuel at high pressure in a large-bore two-stroke engine. Existing combustion chamber geometry is modeled together with proposed valve geometry. The StarCD® fluid dynamics code is used for the simulations, using appropriate turbulence models. High-pressure injection of up to 500 psig methane into cylinder air initially at 25 psig is simulated with the valve opened instantaneously and piston position frozen at the 60 degrees ABDC position. Fuel flow rate across the valve throat varies with the instantaneous pressure but attains a steady state in approximately 22 ms. As expected with the throat shape and pressures, the flow becomes supersonic past the choked valve gap, but returns to a subsonic state upon deflection by a shroud that successfully directs the flow more centrally. This indicates the need for careful shroud design to direct the flow without significant deceleration. Pressures below 300 psig were not effective with the proposed valve geometry. A persistent re-circulation zone is observed immediately below the valve, where it does not help promote mixing.


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