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朴深秀 空軍士官學校 1982 論文集 Vol.15 No.-
The purpose of this paper is to determine the size of ball type EFV(Excess Flow Valve) for automobile. The analytical and experimental methods were employed to measure the discharge coefficient and the choked flowrate. The equivalent nozzle flowrate increased with the increase of d_3 when d_1 and d_2 were fixed. The choked flowrate increased with the increase of d_2 when d_1 and d_3 were fixed. The choke flowrate decreased with the increase of d_1 when d_2 and d_3 were fixed. The size of EFV was determined to meet the legally permitted limits with the capacity of engine displacement up to 1,900cc, according to the obtained discharge coefficient.
박심수,명차리,김한상,황인구 한국자동차공학회 2007 International journal of automotive technology Vol.8 No.5
As current and future automobile emission regulations become more stringent, the research on flow distribution for an exhaust manifold and close-coupled catalyst (CCC) has become an interesting and remarkable subjects. The design of a CCC and exhaust manifold is a formidable task due to the complexity of the flow distribution caused by the pulsating flows from piston motion and engine combustion. Transient flow at the exhaust manifold can be analyzed with various computational fluid dynamics (CFD) tools. However, the results of such simulations must be verified with appropriate experimental data from real engine operating condition. In this study, an experimental approach was performed to investigate the flow distribution of exhaust gases for conventional cast types and stainless steel bending types of a four-cylinder engine. The pressure distribution of each exhaust sub-component was measured using a simulated dynamic flow bench and five-hole pitot probe. Moreover, using the results of the pitot tube measurement at the exit of the CCC, the flow distribution for two types of manifolds (cast type and bending type) was compared in terms of flow uniformity. Based on these experimental techniques, this study can be highly applicable to the design and optimization of exhaust for the better use of catalytic converters to meet the PZEV emission regulation.