MEASUREMENT OF THE INSTANTANEOUS SURFACE TEMPERATURE AND HEAT LOSS OF GASOLINE ENGINE COMBUSTION CHAMBER

The authors, from a viewpoint of heat transfer, found in a steady state as well as in an unsteady state the temperature distribution in a thin film thermocouple to determine the requirements of thin film thermocouple component materials, dimensions and their way of insulation, etc., for a higher precisions measuring, and such requirements were also verified through experiments. In particular, it was known that errors in measuring will be minimum if the thermocouple body material is the same as the measuring point material in thermophysical properties. The authors also developed a means to manufacture thin film thermocouples to measure the surface temperature and instantaneous heat flux of the cylinder liner wall where the piston and the piston rings slide. This was not possible in the past. This report covers a high precision measurement, and the heat loss in cycle of 4-stroke water-cooled gasoline engine known by applying the above measuring method to the piston and cylinder liner.