eng Science and Education Publishing American Journal of Mechanical Engineering 2013-07-30 1 1 119 125 10.12691/ajme-1-5-3 AJME2013153 article Seyed Mahmood Mousavi sm.mousavi.1985@alumni.um.ac.ir 1 Javad Abolfazli Esfahani 1 Masoud Yazdi Mamaghani 1 Mechanical Engineering Department, Ferdowsi University of Mashhad, Mashhad, Iran In the current study, the effect of specific heat ratio, compression ratio, and the maximum to minimum temperature ratio of cycle on the thermal efficiency and the Network of irreversible Diesel cycle have been investigated. For this purpose, numerical solution and multi-objective genetic algorithms with a Pareto optimization method are used to determine the optimum values of specific heat ratio, compression ratio, and the maximum to minimum temperature ratio of cycle. The optimized values of the objective functions (namely Network and thermal efficiency) are then determined by using these vales. The numerical solution shows that the maximum Network and thermal efficiency is obtained simultaneously when the values of specific heat ratio, compression ratio, and the maximum to minimum temperature ratio of cycle are 1.3, 17.7, and 6.0, respectively, and these parameters are obtained by multi-objective genetic algorithms with a Pareto optimization method as 1.3, 17.57, and 6.0. The results obtained from current work are presented in the form of optimal equations for Network thermal efficiency in term of compression efficiency, expansion efficiency and compression ratio of the cycle. The results of current research work can provide a significant insight for optimal design of internal combustion engines including irreversibility. http://pubs.sciepub.com/ajme/1/5/3/ajme-1-5-3.pdf irreversible diesel cycle net work thermal efficiency multi-objective genetic algorithms Pareto method