The passenger car application requires an operating
strategy that retains the concept of non-premixed
combustion and yet, in terms of ignition, moves away
from the conventional diesel cycle combustion process.
One such possibility is the use of surface ignition by means
of a glow plug. Here, following late direct injection, the
outer boundary of the cloud of injected hydrogen, which is
already mixed with air, is ignited by contact with the
surface of a hot glow plug [37]. The resulting combustion
proceeds in a way comparable to a conventional diesel
engine in the cold start phase.