About the Book: The aim of this book is to give a deep insight into the variations of the engine performance, exhaust emissions and combustion characteristics of single cylinder four stroke water cooled stationary C.I. engine using ethanol in various modes. The significance of evaluating the performance, exhaust emissions and combustion characteristics of engine in different modes lies in the fact that the results obtained may facilitate the end-user a great variety of operating conditions for improved performance and/or emissions. Further, the CFD model has also been developed to simulate the combustion phenomenon of the C.I. engine operated on diesel as well as with ethanol the results of the same have been validated with the experimental investigations. The principles underlying the simulation of C.I. engines have been discussed amply which would serve as guidelines for a beginner.