Investigation and optimisation of performance and emission data of CI engine ternary blends under distinct conditions

Abstract

This study investigates the significance of isoamyl alcohol (IAA) in a CI engine by blending with watermelon seed biodiesel (WSB) at preheating and varying load, injection timing (IT), and exhaust gas recirculation (EGR). Adaptive-Network Based Fuzzy Inference Systems (ANFIS), and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) methods were employed to analyze the test results. From statistical indices data, the ANFIS models predicted more accurately. TOPSIS technique confirmed the preheated optimum ternary blend (POTB) as load-12 kg, WSB-5 %, IAA-15 %, IT-25° bTDC, and EGR-21 %. The closeness coefficient values model R² = 0.9736. In comparison to diesel, the POTB blend (WSB5IAA15) offers lower viscosity, density, CN, and heating value, with higher oxygen and latent heat of vaporization (Lv), most of which contribute to improved atomized spray and better combustion. Hence, at load-80 %, POTB to diesel results decrease BTE by 0.11 %, CO by 25 %, CO₂ by 16.39 %, NO_x by 37.08 %, and smoke by 16.16 %, while increasing BSEC by 0.40 %, and HC by 39.83 %. Further, at load-100 %, the results of POTB to diesel diminish BTE by 2.12 %, CO by 14.29 %, CO₂ by 32.89 %, NO_x by 58.12 %, and smoke by 38.13 %, while elevating BSEC by 7.57 %, and HC by 31.30 %. IAA exhibits elevated levels of oxygen, energy density, Lv, and OH active radicals, accompanied by reduced heating value and CN. IAA is crucial in lowering NO_x and smoke levels, which are difficult for WSB to control on its own. Lastly, plots are illustrated for each response parameter to dominant (EGR and WSB) concerning ternary blends and diesel data for specific conditions. Ultimately, the POTB demonstrated that it can serve as an effective diesel fuel substitute.