Combustion and spray breakup characteristics of biodiesel for cold start application

Abstract

This study investigates the split injection spray characteristics of neem (unsaturated) biodiesel and diesel at cold (283 K) and hot (333 K) weather conditions. The novelty of this work lies in achieving the improved spray atomization and smooth engine combustion characteristics of unsaturated neem biodiesel using a split injection strategy. Biodiesel in a hot condition significantly improves spray dispersion and mixing. The Single-injection case of diesel shows fast combustion, rapid heat release, and increased nitrogen oxide (NOx) emissions. Split injection introduces fuel in steps, provides more time for fuel-air mixing, and delays the start of combustion (SoC). Diesel and biodiesel with split injection show smooth heat release, low combustion temperatures, and NOx emissions. Cold condition atomization of biodiesel remains a challenge even using the split injection strategy and requires biodiesel preheating. © 2021 The Authors