International Journal of Advanced Technology and Engineering Exploration, Vol 6(54) ISSN (Print): 2394-5443 ISSN (Online): 2394-7454 http://dx.doi.org/10.19101/IJATEE.2019.650042 126 Diesel engine performance and emission characteristic enhancement using TOPSIS Sunil G Dambhare 1* , Sandeep S Kore 2 , Firoz Z Pathan 3 and Mandar Vahadane 4 Professor, Department of Mechanical Engineering, Dr. D.Y. Patil Institute of Engineering Management and Research, Akurdi, Pune 1 Associate Professor, Department of Mechanical Engineering, Dr. D.Y. Patil Institute of Engineering Management and Research, Akurdi, Pune 2 Assistant Professor, Department of Mechanical Engineering, Dr. D.Y. Patil Institute of Engineering Management and Research, Akurdi, Pune 3 Assistant Professor, Department of Mechanical Engineering, Cummins College of Engineering for Women, Pune 4 Received: 24-March-2019; Revised: 19-May-2019; Accepted: 23-May-2019 ©2019 Sunil G Dambhare et al. This is an open access article distributed under the Creative Commons Attribution (CC BY) License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 1.Introduction The German scientist Rudolph Diesel was a pioneer in the development of fuel injector-based combustion engine. Diesel and gasoline engines, both were crucial in the development of the automobile sector and the transportation industry [1]. Comparing with a gasoline engine, a diesel engine offers advantages of low fuel consumption, high durability, and high thermal efficiency [2]. Worldwide the market share of diesel-powered goods vehicles is increasing, and every third car buyers choose diesel-powered vehicles [3]. On the other side, compared to the conventional catalyst equipped gasoline engine, a diesel engine is a significant contributor of particulate matter and nitrogen oxide (NOx) emissions. *Author for correspondence The combustion efficiency of a diesel engine improves as injection pressure increases [4]. This is due to the better atomization and mixing of fuel and air [5]. The development in the diesel engine was carried out to improve the engine performance and reducing the emissions due to stringent emission norms. One of the methods of controlling NOx emissions is with the help of exhaust gas recirculation (EGR) [4]. As the number of holes in the injector increase, it turns improves the diesel engine performance [6]. The demand for fuel is increasing, and the availability of fossil fuel reserves is limited. The environmental pollutions in the form of greenhouse gas (GHG) emissions, NOx, polycyclic aromatic hydrocarbons (PAHs), particulate matter (PM), and Research Article Abstract The demand for fuel is increasing, and the availability of fossil fuel reserves is limited. The amount of concern arising from the emission problems causing the environment and ecosystem are increasing exponentially. It requires the industry to find the optimum solution. Biodiesel can be stored and used as petroleum diesel. It can be used in blended or pure forms without any modification in the engine. Use of bio-diesel has shown a remarkable reduction of toxic emissions and noise and emissions. This research deals with the use of Jatropha oil as biodiesel to improve the emission characteristics; at the same time, the performance characteristics need to be improved. The diesel engine is optimized with different blends of Jatroha oil as biodiesel, compression ratio, and load using L27 orthogonal array of full factorial design of experiment. The emission parameters, such as HC, CO, and CO2 are measured. The performance parameters viz brake power, brake thermal efficiency, specific fuel consumption, and volumetric efficiency are calculated. The entropy method determines the weight. Optimization is performed using multi-criteria decision-making technique with the TOPSIS method. The results show that blend B10 and a compression ratio of 15 found to be the optimum setting for diesel engine using biodiesel blends to optimize the performance. Keywords Biodiesel, Diesel engine, Design of experiment, Entropy method, MCDM, TOPSIS.