| dc.description.abstract | The fuel economy of recent small size DI diesel engines has become
more and more efficient. However, heat loss is still one of the major
factors contributing to a substantial amount of energy loss in engines.
In order to a full understanding of the heat loss mechanism from
combustion gas to cylinder wall, the effect of hole size and rail
pressure at similar injection rate condition on transient heat flux to
the wall were investigated. Using a constant volume vessel with a
fixed impingement wall, the study measured the surface heat flux of
the wall at the locations of spray flame impingement using three thinfilm
thermocouple heat-flux sensors. The results showed that the
transferred heat was similar under similar injection rate profiles.
However, in case of flame luminosity, temperature distribution,
characteristic of local heat flux and soot distribution was also similar
except the smaller nozzle hole size with higher injection pressure.
Moreover, we confirmed that the relation between Nusselt number
and Reynolds number is a useful measure for describing the heat
transfer phenomena in diesel combustion. | en_US |
