Investigating Scavenge Pressure of a Two Stroke Engine with a View to Alleviate Thermal Conditions 950227
To improve the performance and durability of two stroke engines, pressure, volume and temperature of crankcase are the important parameters which need optimisation. The paper investigates these scavenge parameters of a small two stroke engine with a view to alleviate its thermal conditions.
Investigation of the pressure histories have been done with reference to pressure fluctuations, backflow, Kadenacy effect, list approximation, ring sticking, engine seizure, crankcase volume, crankcase temperature, cylinder barrel temperature, engine speed and physical parameters of the engine. By reducing the crankcase volume by 11 %, the maximum torque has increased by 11 % and shifted from 3000 RPM to 4000 RPM. The maximum power at 6000 RPM has increased by 12 %. Crankcase volume of 2 to 2.5 times the cylinder displacement is considered to be suitable.
An empirical relationship is evolved to predict the temperature in the cylinder barrel, which can be useful to predict temperature of engines within same family.