DefinePK

Abstract

The development of a more efficient engine is an important agenda in the automotive industry and the shrinking source of fossil fuel drives the search for alternative fuels as a replacement for gasoline in car engines. Some of the problems faced by a direct injection engine used today is heat loss to the walls of the combustion chamber. The objective of the study is to determine the combustion characteristics such as the combustion temperature, enthalpy, total energy and local heat flux which use direct injection for various alternative fuels like methane, propane, hydrogen and compressed natural gas. Variables such as the mass flow rate of air, air temperature, ambient pressure and type of fuel are studied to determine the heat loss which occurs so that this data can be used in future researches that involve more specific applications. This study is done using computer simulations with the aid of computational fluid dynamics software. The model used in this study includes non-premixed combustion, P1 radiation, energy equation and large eddy simulation. The results showed that increasing air temperature leads to an increase in heat flux due to more dominant pre-mixed combustion at higher temperatures. An increase in ambient pressure also causes an increase in the mixture density and this leads to a lower heat flux due to narrower combustion. Different fuels show different combustion characteristics. Hydrogen showed the highest heat flux while methane showed the lowest heat flux. This study is a form of fundamental research which allows the data obtained to be used in the development of high efficiency internal combustion engine.