Evaluation of hydrogen premixing impact on 5E concept of CI engine powered by linseed oil and linseed – lemongrass oil blend using RSM-TOPSIS approach

This article aims to study the impact of adding hydrogen to linseed oil and a linseed–lemongrass oil blend on the characteristics of a single-cylinder, 4-stroke, computerized compression ignition (CI) engine. The fuel test matrix was developed using the central composite method, with the loading percentage ranging from 50 % to 100 %. The hydrogen induction level varied from 0 to 10 LPM, and the engine operated on either linseed oil (L100) or a blend of linseed and lemongrass oil (LL50). A response surface model was created and evaluated using ANOVA. The obtained model was deemed satisfactory as both a quadratic and linear model at a 95 % confidence level. Under rated operating conditions, adding hydrogen to LL50 increased its thermal efficiency, exergy efficiency , sustainability index, cooling water exergy, engine exhaust exergy, and BSNO emissions compared to diesel fuel. It also reduced its ExEL, EnEL, TEL , EG , destructed exergy, BSCO , BSCO 2 , BSHC, and smoke opacity. TOPSIS was employed to rank the relationship between input variables and output responses. The optimal operating conditions , achieving a rank of 1, were identified as 75 % loading with 10 LPM hydrogen induction for LL50 fuel. • Linseed-lemongrass oil blend with hydrogen boosts BTE 12.03 % and reduces BSEC 13.68 %. • LL50 with 10 LPM hydrogen improves Acw, Aeg, and ExE while lowering FE 12.03 % and Ad 19.22 %. • Although LL50H10 reduces smoke opacity by 25.11 %, it emits more BSHC, BSCO 2 , BSNO, and BSCO. • The fuel mix and 75 % load with 10 LPM hydrogen are TOPSIS' optimal settings. • In TOPSIS analysis, 75 % load, 10 LPM hydrogen, and fuel mix are idea.