Distribution of Friction and Moment of Inertia in Start of SI Engine 2022-32-0006

In a general-purpose small SI engine, it is required to reduce fuel consumption under the operating conditions of repeated start and stop. In other words, the energy distribution during engine start is an important indicator of 0 rpm until idling speed. The SI engine needs to be driven by the motor at startup, and its electrical energy must be minimized. However, the internal parts of the engine need to accelerate during startup, and its electrical energy is affected by both friction and moment of inertia with the internal parts of engine. The objective of this experimental research are two points. First, it is to determine the friction mean effective pressure (FMEP) under idling speed of the engine. It is important for the finding of the minimum demanded energy in startup to investigate the friction loss of each engine part. Second, it is to find the minimum demand for energy from 0 rpm until idling speed. The minimum demand for energy ought to be determined by the balance of FMEP and moment of inertia.

This research has made it possible to divide and measure the frictional loss and the loss due to the moment of inertia during engine acceleration. To achieve the objective, it is proposed to use the experimental set up that combines the high-speed camera with the engine. The acceleration time in this research, which is the minimum energy in the start of the SI engine, is 2.07s.