Under the Roof of the Cylinder Head-An Experimental Study of the in-Cylinder Air Movement in a Two-Stroke Spark Ignition Engine

In this investigation the in-cylinder flow field structure was evaluated in a small displacement (50 CC) two-stroke spark-ignition engine using cylinders with Schnuerle-ports and a boost-port. A special hot-wire probe was designed, fabricated and calibrated for the use in this work. A constant temperature hot-wire anemometer was used for measurements. The effects of speed, throttle position and piston head shape were studied. The effect of compression ratio, silencer shape and inclusion of resonator to the engine induction and exhaust systems on the in-cylinder flow field activity in the Schnuerle-ported cylinder were analysed. The flow field conditions at different downward locations in the axial direction from the spark point were also evaluated in the Schnuerle-ported cylinder.