Optical access and diagnostic techniques for internal combustion engine development

Methods for optical access to combustion chambers of internal combustion engines are shown. The optical access is either maximised to allow application of complex optical diagnostic techniques whilst maintaining minimum operability of the engine or engine components, or full engine operability is maintained whilst optical access and diagnostic techniques are tailored to the diagnostic demand and the restraints of engine operation. As full optical access allows a wide range of diagnostics to be applied it puts the emphasis on organising and extending realistic engine operation conditions. Full engine operability, however, challenges the optical access and the design of diagnostic systems. The paper gives examples for diagnostic applications for bath of these situations.