The Open Mechanical Engineering Journal
2014, 8 : 185-189Published online 2014 June 13. DOI: 10.2174/1874155X01408010185
Publisher ID: TOMEJ-8-185
Study on Air Flow Characteristics in Cylinders of a Four-Valve Engine with Different Lifts of Valves
ABSTRACT
A 1arge-scale tumble rather than swirl would exist in cylinders in the case of two valves’ opening in a fourvalve engine. A strong swirl is generated when one valve is closed, yet the flow capacity is less than that of two valves being opened. In order to change it, different lifts of valves (DLV) present are achieved. In the case of using different lifts of two intake valves, both tumble and swirl would occur in cylinders, and the flow capacity will hardly change. A new method of measuring the rotational speed of the intake swirl –the method of virtual rotational speed of theory has been put forward. Not only does it eliminate the influence of frictional resistance, but also obtain a theoretic rotational speed, which is only produced by intake swirl.