HEAT TRANSFER IN THE CYLINDER OF A NEW TWO-STROKE CROSS- SCAVENGED ENGINE Rosli Abu Bakar, Devarajan Ramasamy, Chiew Chen Wee Automotive Development Centre, University Teknologi Malaysia (UTM) Fakulti Kejuruteraan Mekanikal, 81310, Skudai Johor, MALAYSIA Phone: 607-5535981, Fax: 607-5566159 E-mail: rosliab@fkm.utm.my ABSTRACT The importance of heat transfer in design of two stroke engine is important to make sure the engine will perform to expectation during actual working conditions. For this a prediction is done on the various heat distribution that might occur during a normal and combustion of the engine. The finite element model was evolved with many boundary conditions that are predicted from theoretical studies. This is to see the general heat transfer of the engine and whether or not the engine will withstand the thermal loads occurring during the theoretical operation. Assumptions are made by approximating temperature to the actual operating condition of the engine. Heat transfer was modeled with conduction as the main source of heat transfer and neglecting convection and radiation. This is because convection is based on gas heat transfer, which is normally very small the same goes for radiation. The values are to be verified when the actual engine is operating with correct boundary conditions. It is hoped that the engine will not come to the boundary applied as it is assumed very high compared to actual condition. The study is a transient study with assumption that the engine is running at 6000 rpm for 60 seconds and generating the boundary heat from theoretical calculations. KEYWORDS: Heat Transfer, Finite Element Analysis 1.0 INTRODUCTION Heat transfer is a very wide field used in analysis of internal combustion engines. Heat transfer effects parameters such as performance, emissions and also efficiency 1 . It is said that for a given mass of fuel the higher the heat transfer to the combustion wall will reduce the average combustion pressure and temperature. This indirectly reduces the work done by the piston per cycle and these effects the specific power. Heat transfer in spark ignition engines is needed to determine thermal stress on material components 2 . This will provide confidence to proceed the project and make sure that the design will not fail due to thermal stresses. Mainly the engine is not fully developed and not tested for any data. So the value of the parameters that are taken for the thermal modeling are based on theoretical values 3 . This will be validated using experiments once the full engine is completed and further help to modify the engine in future works. In