Variation Of Airflow Pattern Through Dissimilar Valve Lift In A Spark Ignition Engine

Abstract

Bi-fuel conversions are a common alternative fuelling option for mono-fuel gasoline SI vehicles because of the minor vehicle modifications required. In Malaysia, most bi-fuel vehicles are fuelled with compressed natural gas (CNG) and gasoline. However, CNG flame speed is lower than gasoline reducing the power and range of the vehicle when operating on CNG. This situation can be improved by increasing the flame speed via higher swirl generation. A computational fluid dynamics model is used to analyse swirl generated by dissimilar valve lift (DVL) profiles on the intake valve. A three-dimensional engine simulation shows differences in swirl motion and turbulence between the original symmetric valve lift profile and the DVL. The higher swirl number reduces the turbulence kinetic energy level slightly. The best case profile is selected for further experimental testing.

Effect of inlet air temperature on SI engine fueled with diethyl ether-gasoline blends

“…This could be due to fuel rich mixture conditions which alters the combustion characteristics and increased CO emission. As the blend percentage increased, the CO emission is decreased which could be due to fuel bound oxygen supports for combustion process [13,31]. The average CO emissions are calculated using weightage factor at 3%, 6% and 9% DEE blend has the reduction of about 10%, 10.5% and 0.05% respectively at the inlet air temperature of 32°C.…”

Effective abatement of diesel engine emissions with split injections

“…However, dilution of charge by using EGR tend to generate more soot emissions, deteriorate fuel consumption along with decrease in engine durability and engine oil quality [14][15][16]. Advancement of fuel injection timing is predominantly used in diesel engines to increase engine performance and combustion quality.…”