1. Introduction
Diesel engine typically operates at higher compression ratio
than gasoline engine, and as such possesses superior thermal effi-
ciency value. Due to this, they are increasingly favoured in recent
years as the prime propulsion system for ground transportation
[1]. This rising popularity of diesel vehicles and the increasingly
stringent diesel emissions standards demand dedicated research
effort to further improve engine output power, fuel consumption
and exhaust emissions [2]. Extensive experimental mappings are
commonly required to evaluate engine-out characteristics,
although this lacks the details of local in-cylinder processes that
actually produce the recorded measurements. However, Computational
Fluid Dynamics (CFD) modelling is becoming an attractive
alternative for engine analysis in place of full experimental testbed
study in recent years. The main thrust for this development
is the level of details provided by CFD simulations on spatial and
temporal variations of local in-cylinder properties, in addition to
the potential savings in terms of time, cost and manpower. CFD
modelling is broadly used by engine researchers to explore in-cylinder
flow fields [3], heat transfer [4], combustion characteristics
and emission formation processes [2,5,6].
Numerous CFD simulation work has been performed to evaluate
flow characteristics during intake and the resulting in-cylinder
bulk gas motion. Among others, Rakopoulos et al. investigated
the effects of crevice flow in internal combustion engines using
simplified CFD crevice model [7]. The main strength of this approach
is that it could be utilised to provide accurate blow-by prediction
even with minimal information on ring-pack configuration.
On the diesel combustion front, CFD investigation on the auto-ignition
of diesel surrogate fuel using detailed kinetics was successfully
conducted by Golovitchev et al. [8]. Here, phenomenological
model was used to capture soot formation under diesel-like conditions
inside a constant volume combustion chamber using the
KIVA-3V code. As a further illustration of the fidelity of this approach,
accurate prediction of soot reduction due to a shorter fuel
injection time in a Volvo AH10A245 diesel engine when fuelled
with neat n-heptane was produced in this simulation study. CFD
modelling has also been used successfully to compliment experimental
test-bed studies, where simulation results generated are
able to elucidate in-cylinder events which produce the observed
change in engine-out responses when intake and operating conditions
are varied. An example of such effort is the work conducted
by Shayler and Ng to investigate the influence of parameters
1. Introduction
Diesel engine typically operates at higher compression ratio
than gasoline engine, and as such possesses superior thermal effi-
ciency value. Due to this, they are increasingly favoured in recent
years as the prime propulsion system for ground transportation
[1]. This rising popularity of diesel vehicles and the increasingly
stringent diesel emissions standards demand dedicated research
effort to further improve engine output power, fuel consumption
and exhaust emissions [2]. Extensive experimental mappings are
commonly required to evaluate engine-out characteristics,
although this lacks the details of local in-cylinder processes that
actually produce the recorded measurements. However, Computational
Fluid Dynamics (CFD) modelling is becoming an attractive
alternative for engine analysis in place of full experimental testbed
study in recent years. The main thrust for this development
is the level of details provided by CFD simulations on spatial and
temporal variations of local in-cylinder properties, in addition to
the potential savings in terms of time, cost and manpower. CFD
modelling is broadly used by engine researchers to explore in-cylinder
flow fields [3], heat transfer [4], combustion characteristics
and emission formation processes [2,5,6].
Numerous CFD simulation work has been performed to evaluate
flow characteristics during intake and the resulting in-cylinder
bulk gas motion. Among others, Rakopoulos et al. investigated
the effects of crevice flow in internal combustion engines using
simplified CFD crevice model [7]. The main strength of this approach
is that it could be utilised to provide accurate blow-by prediction
even with minimal information on ring-pack configuration.
On the diesel combustion front, CFD investigation on the auto-ignition
of diesel surrogate fuel using detailed kinetics was successfully
conducted by Golovitchev et al. [8]. Here, phenomenological
model was used to capture soot formation under diesel-like conditions
inside a constant volume combustion chamber using the
KIVA-3V code. As a further illustration of the fidelity of this approach,
accurate prediction of soot reduction due to a shorter fuel
injection time in a Volvo AH10A245 diesel engine when fuelled
with neat n-heptane was produced in this simulation study. CFD
modelling has also been used successfully to compliment experimental
test-bed studies, where simulation results generated are
able to elucidate in-cylinder events which produce the observed
change in engine-out responses when intake and operating conditions
are varied. An example of such effort is the work conducted
by Shayler and Ng to investigate the influence of parameters
การแปล กรุณารอสักครู่..