n-Butanol and Oleic Acid Methyl Ester, Combustion and NVH Characteristics In Reactivity Controlled Compression Ignition

Abstract Combustion, noise and vibrations produced by n-Butanol and Oleic Acid Methyl Ester (MO) in Reactivity Controlled Compression Ignition (RCCI) were investigated. The Cetane Number was determined using a Constant Volume Combustion Chamber (CVCC) for MO100, ULSD, and n-Butanol and found to be 73.8, 47.2, and 16 respectively. In the case of the MO20Bu80 (Methyl Oleate 20% with 80% n-butanol), the maximum Apparent Heat Release Rate was higher compared to ULSD Classical Diesel Combustion (CDC), due to accumulation of fuel in the combustion chamber because of the longer ignition delay and cylinder and charge cooling effect of n-butanol. RCCI with Methyl-Oleate had a vibrations level of as much 4.5 (m/s2) higher than ULSD in CDC up to 2k Hz. The sound level found by the Acoustic Array sound level for MO20Bu80 in combustion was 4 (dB) louder than ULSD in CDC. RCCI was found to have its own acoustic spectrum compared to CDC, and this is because of the wider range and higher sound levels produced by RCCI. The study suggests that MO can be used as a surrogate fuel for full body biodiesel in RCCI combustion.