Piston Temperature Measurement by Use of Thermographic Phosphors and Thermocouåles in a Heavy-Duty Diesel Engine Run Under Partly Premixed Conditions

Paper i proceeding, 2005

Piston temperature experiments were conducted in a single-cylinder heavy-duty diesel research engine both by use of optical temperature sensitive phosphor and of thermocouples mounted on the piston surface. In the former case, a thin coating of a suitable thermographic phosphor was applied to the areas on the piston surface to be investigated. The optical measurements involved the use of an optical window and of an endoscope. The possibility of using optical fibres into guide light in and out of the engine was also investigated. Results of the optical and of the thermocouple measurements were compared and were also related to more global data with the aim of exploring the use of thermographic phosphors for piston-temperature measurements in diesel engine. Thermographic phosphors thermometry was found to represent an alternative to the thermocouple method since it easily can be applied to various piston geometries.