Abstract
The paper presents a two fold approach to extending conventional engine indication with the capability of visually observing combustion events as they occur in the combustion chamber. In the prototyping phase of engine hardware the influence of port and injector design on fuel-air mixing and the interaction of convective and turbulent gas flow with flame propagation is studied in combustion chamber assemblies. These assemblies comprise of cylinder head prototypes mounted on a standard optically accessed single cylinder test engine. Qualitative and quantitative flow visualisation, the imaging of fuel-air mixing by means of laser-induced fuel fluorescence and flame photography together with conventional engine indication are used for the system analysis. In fully assembled standard engines, flame diagnostics is accomplished by means of tomographic combustion analysis (TCA). The TCA technique allows the continuous, cycle-resolved recording of flame propagation in the plane of the cylinder head gasket. It is capable of observing flame growth and local flame radiation from as soon as the flame penetrates the gasket cross-section until the end of luminous flame radiation.