디젤 배기관내 우레아 수용액의 증발 및 혼합 특성에 관한 연구

Clean diesel and their corresponding post-treatment technologies have been developed to satisfy more stringent emission regulations in the automotive industry. The purpose of this study is to investigate the evaporation and mixing characteristics of the urea water solution injected into the exhaust pipe. After validating the present numerical solution with available data in the literature, the effects of various parameters, such as the injector angle, spray cone angle, and urea mass injected into the exhaust pipe, were investigated. Although the 45-degree injector angle has the most uniform reductant distribution characteristics, the 5-degree injector angle is suitable for diesel exhaust pipes considered in this study due to the wall-wetting of the urea water solution and urea salt. Also, NH₃uniformity is improved by increasing the spray cone angle due to the increase in contact area between the exhaust gas and the urea water solution. Finally, NH3 uniformity is nearly uniform regardless of the injected urea mass.