Quasi-Spherical Combustion Chamber


A fundamental characteristic of any combustible mixture is the laminar flame speed. It affects the propagation/fuel burning rate in any combustion system such as IC engines, gas turbine engines. The laminar flame speed proves to be an important factor in the development of kinetic mechanisms and validation. 

The Spherical Flame Combustion Chamber or the Combustion Bomb is a facility developed by General Motors to characterize the flame speed of any combustible mixture. 

Description of the facility

The internal dimensions of the vessel are 265 mm from window to window and 260 mm in cross sectional diameter at the center. Conical ends sloping to the 92-mm diameter quartz windows give the vessel a “quasi-spherical” shape. The volume is 10.6 L. The facility is designed to operate at pressures up to  40 atm. Ignition occurs in the center of the vessel by the use of two electrodes. Flame structure was observed with high-speed photography through a Z-type schlieren system. 


Quasi-Spherical Combustion Chamber


Laminar Flame Speed Measurements


Laminar flame propagation of a H2-O2 mixture diluted with 79% Helium at equivalence ratio of 0.9.