Sandia addresses barriers to hydrogen-fueled internal combustion engines

Pre-ignition is one of the key barriers preventing hydrogen-fueled combustion engines from achieving efficiency and power-density parity with current diesel powertrains. To address this issue, Sandia has developed an experimental framework to isolate and study various sources of pre-ignition. The research team recently updated the framework with a new methodology that allows the study of oil-droplet-induced pre-ignition under realistic conditions. The method uses a special oil injector that admits a small number of oil droplets into the engine and a multi-camera visualization setup that allows researchers to characterize individual droplet size, track the droplet movement around the engine combustion chamber, and detect droplet-triggered pre-ignition. Early results confirm that oil composition significantly impacts the propensity to trigger pre-ignition and provide insight into how the droplet size, hydrogen concentration, and injection timing impact the likelihood of pre-ignition.

Photo caption: Conceptual schematic of the pre-ignition mechanisms in a hydrogen-fueled internal combustion engine (left). A multi-camera, high-speed system for testing and visualizing oil pre-ignition using Sandia’s optical engine (right).