Optimizing diesel engines with oxyhydrogen dual fuel: Enhancing performance with green methyl ester using MCDM techniques

Abstract The current scenario of the automobile industry states the huge demand and necessity of hydrogen production as well as its storage. An alternative to hydrogen that is widely introduced in recent times is oxyhydrogen gas, often abbreviated as HHO due to its ratio of hydrogen to oxygen (2:1) content. HHO fuel can be extracted using the process of water electrolysis and is free of any carbon content, thus making it a clean fuel. In this present work, two types of fuels are used for carrying out the analysis of a diesel engine. The first one being used is HHO, while the second one is either pure diesel or a mixture of diesel (80%) and Jatropha methyl ester (20%). The study suggested that 20% Jatropha methyl ester (JME20) with HHO reduces the amount of smoke from emission, carbon monoxide (CO) content, and unburnt hydrocarbon (HC) while having an increase of parameters, such as NO x emissions. The desirability approach was implemented in this study to identify the optimal solution out of different combinations. The optimal solution in this study was recorded as Opt.JME20 + HHO fuel at 50% load condition. It has the maximum desirability score of 0.91 and provided the advantages of higher brake thermal efficiency by 1.25%, lower smoke, UHC, and CO emissions by 22.22%, 25%, and 27.27%, respectively, in comparison to the scores of respective parameters in baseline diesel operation.