High Chemical Activity of Incomplete Combustion Products and a Method of Prechamber Torch Ignition for Avalanche Activation of Combustion in Internal Combustion Engines 750890
Aside from the stable products of combustion (CO2 and H2O) and some incomplete constituents (CO, H2, and others) in the flame front of a hydrocarbon-air mixture, there are also formed various concentrations of components of intermediate chemical reactions. Studies in cyclic and stationary flames of the kinetic formation, heat and temperature of catalytic recombination of these components, establish the unusually high concentration of ionized atoms and radicals (H, CH, C2, and others) in the branching chain reactions which can exceed the thermodynamic equilibrium by an order of two to four. These are formed in the flame of a rich mixture possessing a 30 to 60% insufficiency of air. The ionized atoms and radicals are short-lived but can initiate specific chemical activity during their life span of 5 to 10 ms. The concentrations of these reactive elements sharply diminish as the rich mixture is leaned toward stoichiometric.
An analysis of the hydrodynamical structure in the combustion zone, which is initiated by the burned products of combustion fed from an auxiliary combustion chamber, led to the discovery of a means to develop turbulent vortex kernels in the wake of the prechamber torch to achieve rapid and efficient combustion. Optimization is achieved by employing a prechamber volume of 2 to 3% of the compressed combustion chamber volume, employing connecting channels with an area of 0.03 to 0.04 cm2 per 1 cm3 of the prechamber volume and employing channels with a length to diameter ratio of 1/2.
Out of this research work has evolved the “LAG-Process” of combustion which utilizes the high chemical activity of the products of incomplete combustion of a rich auxiliary mixture to produce fast, complete, and stable combustion in the working main mixture within the combustion chamber of various types of engines. The delay period of ignition of the main mixture is decreased by 5 to 7 times and the combustion duration is significantly decreased by 3 to 4 times in comparison to spark ignition. A 10% improvement in combustion efficiency is achieved and the overall combustion becomes exceptionally stable and reproducible.
Citation: Gussak, L., Turkish, M., and Siegla, D., "High Chemical Activity of Incomplete Combustion Products and a Method of Prechamber Torch Ignition for Avalanche Activation of Combustion in Internal Combustion Engines," SAE Technical Paper 750890, 1975, https://doi.org/10.4271/750890. Download Citation
L. A. Gussak, Michael C. Turkish, Donald C. Siegla
SAE Automobile Engineering and Manufacturing Meeting