Cinematography of Combustion in Diesel Engines

Abstract

Methods used to film the injection and combustion processes in some forms of diesel combustion chamber are described. Rates of up to 15,000 frames/sec. were used with suitable lighting to show the distribution of injected fuel prior to self-ignition. Pressure, injector needle motion, crank angle and time were recorded in addition to the visual picture. Two synchronised cameras were used with semi-automatic control gear to get a correct sequence of operations. An improved accelerator was devised for the Fastax camera used for the visual pictures. The field of this camera was split into two halves with a supplementary lens in one path to cover two areas at different distances from the camera. Perspex (polymethyl methacrylate) was used for combustion chamber windows in spite of the high temperatures and pressures. Lighting, processing methods and choice of sensitive materials are also dealt with. In recording data on 70 mm. paper, an artifice was used to increase temporal resolution.