Application of cycle skipping methodology in a single cylinder spark ignition engine

Initially focused on Otto cycle, its differences from ideal to real cycle conditions and causes of these differences. Then, the gain has been derived for the proposed cycle skipping methodology considering the thermodynamically ideal conditions. Experimental part of this study was done systematically by making targeted modifications and upgrades on a chosen single cylinder research engine in Yildiz Technical University Automotive Laboratory. Experiments consist of three stages; power measuring by an external drive, fuel consumption measurements for both idling and cycle skipping conditions. The external drive experiments which are defined as motoring, are mainly due to measure the consumed power of experimental engine at different throttle positions. Idling condition experiments aim to measure idle fuel consumption by using different cycle skipping methods. The partial load cycle skipping tests, which are our particular interests, has been applied several times at various mean effective pressure and speed intervals. As a result of the cycle skipping experiments, brake specific fuel consumption and emission values are reduced for pre-determined conditions at partial load region. As expected, provided gain has also been reduced by increasing load and engine speed. Keywords: Cycle skipping, Otto cycle, partial load.