Abstract
This research aims to develop parts for advanced air (blow-by) / oil separation capability for regulation proof engines. These parts can play a role of converting traditional air emission type crankcase into closed breather type crankcase ventilation rerouting blow-by to airintake through air-oil separator jointed to cylinder head cover so that the engine can deal with environmental regulations, which do not allow minimal amount of toxic gas discharge. However, the separation efficiency is hardly predictable before experimental test was performed. Computational simulation has been conducted to analyze and predict the efficiency of air-oil separation performance of the engine. In this study, separation performance classified by diameter of oil mist in cylinder head cover which has nozzles, impact plates and baffle plates is calculated with CFD DPM (Discrete Phase Model) method. DPM method is Particle (Oil) tracking simulation with a probabilistic collision model. Basically, under hot running engine system oil exists as gaseous state not a particle. But, numerical cost to solve two-phase equation, gaseous and condensed oil, is extremely high which is not appropriate for the commercial purpose even though it is realistic. In this research, numerical calculation by DPM method is compared and validated with experimental results to apply for commercial purpose and efficiency improved models are suggested to offer design guide by using DPM method.