High-speed video characterisation of Bosch heavy duty injectors

The project proposed to use macroscopic high-speed video to characterise the sprays’ morphology. The experimental work was performed within an optical rapid compression machine dedicated to the study of diesel fuel injection.

The Proteus rapid compression machine offers a large optical access and can be operated over a wide range of ambient conditions to allow testing different injectors, nozzles and fuels. The optical Proteus is currently fitted with a Delphi medium-duty common rail system, which includes a DFP3 pump and rail rated at 2000bar.

Tests were conducted to visualise the evolution of liquid spray penetration with time. This was achieved by using a state-of-the-art high-speed visualisation system, which includes a 50kHz copper vapour laser and a VisionResearch Phantom v12.1 monochrome high-speed camera.

The data set consisted of high-speed videos of the liquid phase of the spray, recorded by light scattering, and high-speed videos of the vapour phase of the spray recorded by Schlieren imaging.

All videos were recorded at a frame rate of approximately 40,000 frames per second from the start of injection and a pixel resolution of approximately 512x256 pixels.