Evaluation of Noise and Air Flow on a Motorized Adaptive Valve Lift and Timing Engine

摘要

This paper explains about the evaluation of intake air flow, volumetric efficiency and noise of a motor-driven engine that used an adaptive valve lift and timing mechanism (AVLT) on one intake valve. This system is developed with an aim to produce a more powerful engine through variable valve timing and lift technique. The system made the valve lifts higher without increasing the valve lift duration. Therefore, a dynamic valve lift profile with respect to the engine speed can be achieved thus varies the input and output of an engine. As a result of applying the AVLT on a motor-driven engine, the engine noise, emission noise and the mass air flow entering the engine cylinder was increased. When AVLT is employed to a maximum lift, the mass air flow of default intake valve lift was improved within a range from 8% to 46.64% in 500 rpm to 2000 rpm speed range. Maximum lift produced engine noise within a range of 2.57% to 18.13% higher than the default lift throughout all speed. Also, maximum lift produced emission noise within a range of 2.47% to 19.19% higher than the default lift throughout all speed. The product of this research will be useful to optimise the height and timing of the valve lift and the AVLT mountings on the engine head during operation thus improves the engine performance, fuel economy, emission levels and reduced noise of a modified engine.