Abstract
Although the electric motorcycle has been introduced in the market, but it still cannot replace the wild usage of IC engine motorcycle in the populated Taiwan. The pollution caused by the emission of motorcycle has been under control by government. Most of research articles have taken the view from engine combustion regarding to the pollution problems. But in the process of engine combustion, no matter the liquefied fuel is rich or lean. The pollutant inside the engine can still occur. That is because uneven temperature distribution of the inner surface of engine cylinder. The surface with lower temperature will release HC and CO, while surface with higher temperature will produce NO.The present study of physical model is a annular fin, one adopt the numerical method by the centeral difference and P-Method. For the heat transfer coefficient of fin, one guess a value of h, and subseience the value into governing equation and boundary condition. After the transient temperature distribution was obtained by the numerical calculation. Then, the temperature distribution was compared with that of experiment. One can guess the h continuously, until the value was match to the experimental value, therefor this value of h is the correct heat transfer coefficient of this study.