EFFECT OF COMPRESSION RATIO ON PERFORMANCE OF 1-CYLINDER ETHANOL-POWERED ENGINE RUNNING IN TRANSIENT CONDITION

• Main Author: Sinaga, Agustinus
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/49070
• Institution: Institut Teknologi Bandung

Ethanol is one of the most promising alternative fuels as a potential substitute for gasoline as the fuel for spark ignition engines. The application of ethanol as a fuel is being researched by Rakata Team ITB to develop the most efficient ethanol-powered car. In the research, a lot of modifications are performed to the gasoline engine and one of the most important is the engine compression ratio. This research aimed to analyze the effect of compression ratio on effective power and efficiency of a 1-cylinder ethanol-powered engine as the prime mover of Rakata Team’s cars. The engine was operated in wide-open throttle and at transient condition, to simulate the driving method of the team’s car, which is coast and burn. The compression ratio was varied from 10:1, 11:1, 12:1, 13:1, 14:1, up to 15:1 using the engine’s original ECU without any modification. The experiment was performed on a dynamometer chassis to obtain the engine rpm, torque, and power while the fuel consumption rate was measured using flow meter. The experiment result shows that increasing compression ratio results increase in power and effective efficiency in almost every rpm. By using the effective efficiency results obtained from the experiment to predict the effective efficiency for higher compression ratio, it is projected that the average effective efficiency for compression ratio of 16:1, 17:1, and 18:1 are 39.03%, 41.6%, and 46.7%. respectively. Both the experiment and the projection show that an increase in compression ratio will result in an increase of 2.5% of average effective efficiency. Thus, increasing engine compression ratio is one of the alternatives in increasing Rakata Team’s car efficiency.