2011 : Design and Simulation of a Single Cylinder High Speed Spark Ignition Linear Engine with Spring System

Ir. Aguk Zuhdi Muhammad Fathallah M.Eng, Ph.D


Abstract

This thesis deals with the design of a single cylinder high-speed spark ignition linear engine with a spring system return cycle. The main objective of the research is to design and analyse a free piston linear engine that is easy to start, easy to maintain and easy to control. The unique design of the spring as a return cycle in a free piston linear engine is presented and its effects on engine performance and motion are discussed. The engine performance has been predicted the aim is to design a linear engine particularly for the spring system. The spring design has been optimised by using a multilevel optimization approach. Based on the optimisation of the spring design, the linear engine geometry design has been conducted. The performance of the linear engine design has been measured and the results compared with the predicted performance. Besides which the motion of the linear engine has been studied; however, friction affect show the rotated of the piston. It is necessary to modify the spring mechanism to ensure that the scavenging process works properly. Two scenarios such as the removal of the bottom part of the piston skirt and adding a lock to the connecting rod are recommended, based of structural stress and thermal-structural stress analysis. Software has been used in the research to analyse the design of the free piston linear engine with a spring system, including GT-Power, SolidWorks, Matlab, Algor, and Spread-Sheet. The model has been built using GT-Power to predict the engine performance. To validate the model, it has been assessed with the original engine manual and experimentally. Three step multilevel optimisation of …