Over the past few decades, Homogeneous Charge
Compression Ignition (HCCI) or Controlled Auto-Ignition
(CAI) if it is fuelled with gasoline type of fuels has shown
its potential to overcome the limitations and
environmental issue concerns of the Spark Ignition (SI)
and Compression Ignition (CI) engines. However,
controlling the ignition timing of a CAI engine over a
wide range of speeds and loads is challenging.
Combustion in CAI is affected by a number of factors;
the local temperature, the local composition of the
air/fuel mixture, time and to a lesser degree the
pressure. The in-cylinder engine charge flow fields have
significant influences on these factors, especially the
local gas properties, which leads to the influences
towards the CAI combustion. In this study, such
influences were investigated using a Computational
Fluid Dynamics (CFD) engine simulation package fitted
with a real optical research engine geometry. Applying a
Laser Doppler Anemometry (LDA) to the same engine,
the cycle averaged time history mean and Root Mean
Square (RMS) velocity profiles for the axial and radial
velocity components in three axial planes were
measured throughout the inlet and compression stroke.
The calculated results were compared with the
experimental results in terms of the vectors flow fields,
averaged integrated tumble ratio as a function of crankangle
and the local velocities in this paper. The results
from both studies showed good correlations