The flame propagation pattern in a 2-stroke gasoline engine has been investigated by adopting the IPG(Ionization Probe Gasket), which contains six identical ionization probes equally spaced arround its periphery. The IPG was constructed by joining two sheets of paper gaskets and it was installed between the engine head and cylinder block. By decting the flame travel interval to the six ionization probes, the flame propagation pattern can be inferred. The shape of flame front was obtained by using the cubic spline interpolation. The engine was run at various speeds, loads, and spark plug locations. It was found that the flame travel interval increases with the engine speeds and loads. In addition, as the spark plug location approaches the exhaust port, the eccentricity of flame shape increases.
This technique can be used as one of the useful methods to dectect flame propagation pattern in production engine without any modification.
