• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2000.05a
• /
• pp.52-59
• /
• 2000

Experimental studies were performed to improve the THC emission characteristics by optimizing the flow in the exhaust manifold and CCC in a SI engine. For this purpose the flow characteristics in the exhaust manifold and CCC were measured by using LDV technique under various engine conditions, Referring to these data a new type exhaust manifold was designed to improve the cold-start emission characteristics and the response characteristics of {{{{ OMICRON _2}}}} sensor by optimizing the flow pattern and reducing the thermal inertia of the exhaust manifold system. It was found through the vehicle emission tests that the emission characteristics of THC of the new type exhaust manifold was improved by 12% through the optimizing the flow pattern in the exhaust manifold.

• 한국연소학회:학술대회논문집
• /
• 2004.11a
• /
• pp.217-222
• /
• 2004

In recent year, as the current and future emission regulations go stringent, the research of exhaust manifold and CCC has become the subject of increasing interest and attention. This study is concerned with the systematic approach to improve catalyst flow uniformity and light-off behavior through the basic understanding of exhaust flow characteristics. Computational approach to the unsteady compressible flow for exhaust manifold of 4-1 type and 4-2-1 type and CCC system of a 4-cylinder DOHC gasoline engine was performed to investigate the flow distribution of exhaust gases. In this study, through calculation, the effects of geometric configuration of exhaust manifold on flow structure and its maldistribution in monolith were mainly investigated to understand the exhaust flow patterns in terms of flow uniformity. Based on the design guidance resulting from this fundamental study, the flow uniformity of 4-2-1 type exhaust manifold demonstrated the more improved exhaust characteristics than that of the 4-1 type one.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.31 no.3 s.258
• /
• pp.338-343
• /
• 2007

Thermal deformation of cast iron exhaust manifold for turbo diesel engine is investigated by finite element analysis (FEA). The FE model included the temperature dependent material properties as well as the interactions between exhaust manifold, cylinder head and fasteners. It also considers the sliding behavior of the flanges of exhaust manifold on cylinder head when either expansion or contraction of the exhaust manifold exceeds the fastener pretension. The result of analysis revealed that remarkable thermal deformation along the longitudinal direction. Compressive plastic deformation at high temperature remained tensile stress in manifold and resulted in longitudinal contraction at ambient temperature. The amount of contraction at each fastener position was predicted and compared with experimental results. Analysis results revealed that the model predicted deformation qualitatively, but more elaborated cyclic hardening behavior would be necessary to predict the deformation quantitatively.

• International Journal of Automotive Technology
• /
• v.5 no.4
• /
• pp.297-302
• /
• 2004

This paper presents the low cycle thermal fatigue of the engine exhaust manifold subject to thermo-mechanical cyclic loading. As a failure of the exhaust manifold is mainly caused by geometric constraints of the less expanded inlet flange and cylinder head, the analysis is based on the exhaust system model with three-dimensional temperature distribution and temperature dependent material properties. The result show that large compressive plastic deformations are generated at an elevated temperature of the exhaust manifold and tensile stresses are remained in several critical zones at a cold condition. From the repetition of these thermal shock cycles, maximum plastic strain range (0.454%) could be estimated by the stabilized stress-strain hysteresis loops. It is used to predict the low cycle thermal fatigue life of the exhaust manifold for the thermal shock test.

• Journal of Advanced Marine Engineering and Technology
• /
• v.24 no.5
• /
• pp.111-118
• /
• 2000

Experimental studies were performed to understand the flow characteristics in the exhaust system and improve the THC emission characteristics by optimizing the flow in the exhaust manifold and CCC in a SI engine. For this purpose, the flow characteristics in the exhaust systems with two types of exhaust manifolds(STD and New Type) were measured by using LDV technique under various engine condition. It was found that the flow characteristics in the New Type exhaust manifold was more desirable in a view point of heat loss reduction from the exhaust gases. The vehicle emission tests showed that the THC emission in the New Type exhaust manifold was decreased by 12%.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2008.05a
• /
• pp.209-212
• /
• 2008

Hydroforming Technology has been applied to manufacture in various parts of automobile. Especially, Exhaust manifold has been applied to hydroforming method in the foreign advanced automotive company. Exhaust manifold runner is important exhaust parts that heat-resistant and exhaust flow characteristics are requested in the automobile. The purpose of this study is to optimize the manufacturing method of exhaust maniflold runner using FEA and to propose to get a optimization design direction. In addition, Comparative analysis between conventional exhaust maniflold and hydroformed exhaust maniflold has been done in view of weight-saving, manufacturing advantage.

• Journal of Advanced Marine Engineering and Technology
• /
• v.37 no.7
• /
• pp.694-700
• /
• 2013

The design of the exhaust manifold for the pulse converters of a 4 strokes high power medium-speed diesel engine is presented in terms of fatigue analysis. The said system undergoes thermal expansion due to high temperature of exhaust gas and is exposed to intrinsic vibration of the internal combustion engine. Moreover, the exhaust pulse generates pressure pulsating along the runner inside manifold. Under such circumstances, the design and construction of exhaust manifold must be carried out in a way to prevent early failure due to fracture. To validate the design concept, a test rig was developed to simulate the combination of thermal and vibrational movements, simultaneously. Experimental results showed that a certain sense of reliability can be achieved by considering a field factor obtained from the results of engine bench tests.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.15 no.1
• /
• pp.139-145
• /
• 2007

This paper presents the low cycle thermal fatigue of the engine exhaust manifold subject to thermomechanical cyclic loadings. The analysis includes the FE model of the exhaust system, temperature dependent material properties, and thermal loadings. The result shows that at an elevated temperature, large compressive plastic deformations are generated, and at a cold condition, tensile stresses are remained in several critical zones of the exhaust manifold. From the repetitions of thermal shock cycles, plastic strain ranges could be estimated by the stabilized stress-strain hysteresis loops. The method was applied to assess the low cycle thermal fatigue for the engine exhaust manifold. It shows a good agreement between numerical and experimental results.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.10
• /
• pp.5912-5918
• /
• 2014

Owing to highly developed industries and the use of fossil fuels, environmental problems becoming becoming pressing issues globally. Therefore, a study of automobile exhaust is urgently needed. Generally, air is sucked into the engine through the intake manifold. The aims of this study were to reduce the exhaust from used cars and increase the output by removing carbon deposits, which are considered a reason for the increasing exhaust and reduction of output, and the reduction of exhaust, variation of output and stability of idle speed were analyzed. The formation of carbon deposits within the suction manifold was investigated through a test device (KD147). In the intake manifold, the exhaust cleaning effect was confirmed.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.27 no.7
• /
• pp.837-844
• /
• 2003

The exhaust gas flow in the inlet collector of close coupled catalyst(CCC) adapted to the exhaust manifold is very complex flow because the exhaust gas is a pulsation flow with several port flow. The distribution of gas flow and temperature in inlet collector effect to the efficiency of catalytic converter. In this study, it measures temperatures on several point in inlet collector with two kind of inlet collector volume. And it analyzes with CFD to exhaust manifold and close coupled catalyst for temperature and flow. Comparing to measured and analyzed result, it find increasing of collector volume effects to catalyst temperature distribution and uniformity of catalytic converter