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The interaction between a combusting diesel spray and a wall was studied by measuring the spray flame temperature time and spatially resolved. The influence of injection sequences, injection pressure and gas conditions on the heat transfer between the combusting spray and the wall was investigated by measuring the flame temperature during the complete injection event. The flame temperature was measured by an emission based optical method and determined by comparing the relative emission intensities from the soot in the flame at two wavelength intervals. The measurements were done by employing a monochromatic and non intensified high speed camera, an array of mirrors, interference filters and a beam splitter. The studies were carried out in the Chalmers High Pressure High Temperature (HP/HT) spray rig at conditions similar to those prevailing in a direct injected diesel engine prior to the injection of fuel.

An abridged method for high speed shadowgraph and diffraction based imaging of combusting sprays, capable to discern among spray and flame regions is presented and discussed. The measurements were done in a pressure and temperature controlled combustion chamber under conditions similar to those prevailing in a direct injected diesel engine. A set of examples are shown where the visualisation and localisation of the liquid and gas phases of reacting sprays are possible regardless of the injection sequence which is implemented. Further, the penetration of the liquid and gas phases can be measured along a single injection with the possibility of doing spray characterisation and combusting studies of a single spray spatially resolved and as function of time.