High bandwidth heat transfer and optical measurements in an I.C. engine

Three independent measurements have been used to investigate combustion within a single cylinder four-stroke research engine operating at low load. 1) thin film gauges. Heat transfer is determined using platinum thin film resistance thermometers exposed to the combustion gases. These give a frequency response of greater than 100 kHz; hence can track heat transfer rate changes on the piston and cylinder head surfaces adequately. 2) fibre optic instrumentation. Combustion is a highly complex process where the mechanism of fuel oxidation causes many different chemical species to emit light on specific spectral lines; therefore, from a measured emission spectrum it is possible to infer the chemical species present Measurements of the spectral content (300 to 850 nm) of the light intensities within the combustion chamber are presented. 3) high speed video. A 500 fps colour video camera was used to record a series of images of the firing cycle with a high spatial and temporal resolution through a cylinder head modified for optical access.. The three techniques form part of a data fusion study researching the application of data processing techniques in complex multidimensional areas such as combustion.