Measurements of flame propagation in a rotary engine using rotor-installed ionization gaps

Abstract

The combustion in a rotary engine has been investigated in terms of the flame propagation on the rotor flank and the information obtained simultaneously from the working chamber pressure. An experimental overhanging eccentric shaft-type single rotor engine was used, which was equipped with a multichannel packaged slip ring to take out the signals of 15 uniformly-spaced ionization gaps on the rotor flank. The measurements were made under the experimental conditions of various air fuel ratios, ignition modes (leading spark plug only and trailing spark plug only, dual spark plugs and triple spark plugs) and intervals between leading and trailing spark timings. The effects of flame propagation patterns on P-V diagrams, heat release rates, indicated mean effective pressures and indicated specific fuel consumption ratios are discussed. The flame propagation at the center in the rotor width direction was found to occur in order of the front part, the rear part, the center part of the rotor recess, the front part of the leading side of the rotor, and the rear part of the trailing side. Also the flame could propagate to both corners on the rear part of the trailing side of the rotor later than 150°ATDC.