The role of 1.8-cineole addition on the change in triglyceride geometry and combustion characteristics of vegetable oils droplets

[Display omitted] •1.8-cineole increases the reactivity of fuel molecules thus improves combustion performance.•1.8-cineole delocalized electron and polar charge enlarges the triglyceride geometry.•Enlarged geometry increases electron mobility and provide extra space for atom to move.•Addition 1.8-cineole in vegetable oil improves the physical and chemical properties of vegetable oil that may improve the engine performance. The use of Crude Vegetable Oils (CVO) in diesel engine faces several problems related to viscosity and combustion characteristics. This research aims to reveal the role of 1.8-cineole on performance characteristics of vegetable oil droplets. In this study, bubble growth, ignition delay, micro-explosion, and flame evolution process with and without 1.8-cineole in CVO has been studied experimentally at atmospheric pressure and room temperature. Droplets are examined using classical high-speed imaging techniques. The result shows that 1.8-cineole decreases all the various ignition delay into uniform time delay except for the non-polar Crude Jatropha Oil (CJO) compounds are more saturated, larger molecule and stiffer. Magnetic field produced in aromatic ring of 1.8-cineole assisted by strong electric chard in its oxygen atom induces electron in fuel molecules to become more reactive. Moreover, the 1.8-cineole compound crooked the molecular chain of triglyceride on Crude Coconut Oil (CCO), Crude Palm Oil (CPO), and Crude Sunflower Oil (CSFO) to bend apart from each other even longer, when compared to that of CJO, therefore, lowering viscosity and increasing volatility and increasing the burning rate. The polarity of the four droplets has high impact on the influence of 1.8-cineole on the performance of oil droplets in the process of evaporation to the ignition.