As the environmental disruption caused by the mass supply of vehicles is emerged as one of the serious problems, new cars with low pollution problems and high efficiency is needed. Because the low combustion engine is essential for the high efficiency car, diesel cars has attained attention.
The low pollution regulations of the high efficiency diesel cars are classified by engine technique, fuel technique and post treatment technique. Now the study of engine technique and fuel technique is actively proceeding but it is difficult to satisfy the regulative levels only with the engine technique and fuel technique, as the regulations on exhaust fumes have escalated. Accordingly, many attempts on post treatment system have been proceeding and more technical developments are required. With regard to the post treatment system, exhaust fumes which is the major reduction target, are divided into PM and NOx. Owing to the technical development of DPF, PM is successfully reduced about 90%. In contrast with PM, the reduction technique on NOx is still on developing and the various techniques, such as LNT, LNC, SCR, etc., are presented. Among SCR methods, many advanced countries are actively proceeding the R&D of Urea-SCR, which is expected to be a leading NOx reduction technique hereafter.
This study is mainly purposed to investigate the mixed features of spurting urea in SCR system, through analysing the fluid of Urea-SCR system in the exhaust part of vehicles by Fluent, commercial code. Also, this study investigates the features in case of spurting Water which has similar material property to urea, using Discrete Phase Model in Fluent and defines the factors having influences on the mixing rates of water with air, such as the numbers of wings and angle in Mixer.
