Date of Award
Master of Science in Engineering
Mechanical and Aeronautical Engineering (to 2013)
Dr. Ho Sung Lee
Dr. Chris Cho
Dr. Bade Shrestha
Dr. Claudia Fajardo
Masters Thesis-Campus Only
Previous studies have shown that increasing the coolant temperature in the internal combustion (IC) engine improved engine performance, especially in brake power and fuel consumption. To have more of an understanding about the reasons behind these improvements, a study of the cylinder from the inside was needed. Therefore, a study was conducted to study the effects of increasing the coolant temperature (from 90°C to 120°C) under five different loads (from 20% to 100%) by using a four-cylinder, 1.6L spark ignition (SI) engine in the automotive laboratory at Western Michigan University. In order to measure the indicated work and spark timing, a spark plug with pressure transducer and optical angle encoder were newly installed in the engine. The heat flux, energy balance, and thermal efficiency were calculated under different coolant temperatures and different loads. The study found that the heat flux between the combustion chamber and coolant in the cylinder head increases with an increase of coolant temperatures under different loads.
On the other hand, the indicated work remained steady with the increase of the coolant temperature. Finally, the spark timing retarded when the coolant temperature was increased; an effect that could be seen more clearly with higher loads.
Attar, Alaa M., "The Effects of Coolant Temperature on Spark Ignition Engine Performance" (2012). Master's Theses. 270.