THE VOLUMETRIC EFFICIENCY OF A SINGLE-CYLINDER SPARK-IGNITION ENGINE AS AFFECTED BY AIR INTAKE TEMPERATURE AND HUMIDITY

Nowadays, there are an increasing demand for energy efficiency and emission reduction by the internal combustion engine. It can be achieved by improving the volumetric efficiency of spark ignition engine. The air intake temperature and humidity give an impact to the volumetric efficiency. Thus, the goal of this study is to investigate the impacts of air intake temperature and humidity on the volumetric efficiency of a single cylinder spark ignition engine. This study was facilitated using Altair HyperStudy. It was executed by full factorial design of experiments (DOE). The effects of engine speed, air intake temperature, and humidity towards the volumetric efficiency was assessed based on one-dimensional engine simulation. The ANOVA analysis showed a positive correlation between engine speed and volumetric efficiency. There is a negative effect found for the air intake temperature. However, a negligible impact of humidity obtained in this study. The optimal configuration for achieving a maximum volumetric efficiency of 0.97 was identified at 4500 RPM, 26 degrees Celsius, and 68.0% humidity. It is suggested by the results that while engine speed has a significant impact on volumetric efficiency, temperature and humidity also play important roles in optimizing engine performance. These insights are valuable for designing and operating more efficient and environmentally friendly engines.