What is CCAI ?
For the Diesel Engine ,it depends on the type of fuels.The cetane numbers are used for the distillate fuels.
Two other empirical indices are used for the residual fuel oil: CCAI and Calculated Ignition Index (CII).
Both CCAI and CII are calculated from the fuel density and kinematics Viscosity.
Formula for CCAI:
Normally, this will give a value somewhere between 800 and 880. The lower the value, the better the quality of the ignition. Fuels with a Calculated Carbon Aromaticity Index higher than 880 are often problematic or even unusable in diesel engines.
A Low Calculated Carbon Aromaticity Index Rating means better Ignition,Better fuel quality and less Ignition Delay.
Low Ratings are up to a Calculated Carbon Aromaticity Index ratio of 850
Range :- 850-950 ;870 be the limit for use.
Medium speed engine – < 840
For Slow speed engine – < 870
Full form :-
Calculated Carbon Aromaticity Index