Technical Paper
Instantaneous Heat Transfer in a Highly Rated DI Truck Engine
1990-02-01
900692
The spatial variation of instantaneous heat transfer in a highly rated DI diesel engine (130 mm bore, 150 mm stroke) has been investigated. Measurements have been made at key locations within the combustion chamber (valve bridge, above the piston bowl lip and bore edge) at test conditions covering the engine speed and load range. Total and radiative heat flux probes have been designed and developed to enable both the convective and radiative heat transfer components to be quantified. Transient calibration techniques have also been developed to establish the dynamic characteristics of the heat flux probes. This has removed the uncertainty normally associated with surface thermocouple diffusivity values. Considerable spatial variations in both peak and mean heat transfer have been found. The measured spatial and temporal variation in heat flux have been compared with established heat transfer models.