The OACIC is an optical reciprocating rapid compression machine for studies of combustion in an engine environment and is equipped with windows, enabling line-of-sight optical measurements of the reacting spray under CI engine conditions. The data acquisition, temperature control, tracking of crank position and triggering of injector are all programmed in Labview.
The method used for measuring soot is diffuse back-illuminated extinction imaging (DBIEI) of soot particles. The method is based on the light extinction from particles present in the light path, where the extinction of light is the sum of the light intensity scattered and absorbed by the particles.
The exhaust gas composition is measured using a HORIBA gas analyser for gas species and a Cambustion DMS500 to determine the size and number density of the exhaust particulate matter.