• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.5
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• pp.58-65
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• 1994

In order to reduce particulate emissions from diesel vehicles, mathematical model is established and analyzed on ceramic wall-flow monolith filter. A wall-flow monolith filter placed in the exhaust stream of a diesel engine can effectively limit the emission of diesel particulates through the monolith. The accumulated particulates can then be periodically combusted inside the monolith by directing hot gas to the monolith while normal engine exhaust is routed around the monolith system. The resulting low flow rates through the monolith require consideration of gas dynamics through the channels as well as particulate combustion to analyze this regeneration process. A mathematical model of the regeneration is formulated as a system of nonlinear partial differential equations describing the conservation of mass, momentum and energy. Numerical solutions are obtained by using a finite difference techniques for the spatial discretization. So we can use filter simulation program for the purpose of filter design and actual filter regeneration

• Journal of the Korean Society of Visualization
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• v.19 no.3
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• pp.130-135
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• 2021

Water vapor has received worldwide large attention due to its broad technological implications ranged from resource production and environmental remediation. Especially, one of the typical areas where the water vapor is important is the removal of PM (particulate matter) which causes a critical hazard to human health. However, most vapor-based PM removal methods are limited in removing PM2.5 by using relatively large water droplets and consume large energy. Here, we propose a superhydrophilic thermally-insulated macroporous membrane to generate steam flow. The water vapor directly captures PM with steam flow and hygroscopic characteristic of PM. The steam, the cluster of water vapor, from the membrane gives rise to high removal efficiencies compared to those of the control case without light illumination. To reveal PM removal mechanism, the steam flow and PM were quantitatively analyzed using PIV measurement. The proposed steam generator could be utilized as an economical and ecofriendly platform for effective PM removal at a fairly low cost in a sustainable, energy-free, and harmless-to-human manner.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.1
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• pp.78-88
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• 2007

In the present study a detailed examination of various porous media models for predicting filtration efficiency and pressure drop of diesel particulate filter (DPF), such as sphere-in-cell and constricted tube models, are attempted. In order for demonstrating their validities of correct estimation on permeability, geometry of property configurations common in commercial cordierite DPFs are correlated to the porous media flow models, and validations of predicted filtration efficiencies due to the use of different unit collectors are made with experiments. The result shows that the porosity, pore size and permeability of cordierite DPF can be successfully correlated by Kuwabara flow field with correction factor of 0.6. The unit collector efficiency predicted by sphere-in-cell model agrees very well with measurements in accumulation mode, whereas that by constricted tube model with significant prediction error.

• Journal of the Korean Society of Safety
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• v.23 no.5
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• pp.7-14
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• 2008

The temperature distribution in a surface of diesel particulate filter(DPF) was measured using an infrared temperature camera. In order to regenerate the DPF, five partitioned electric heaters were used for heating the ceramic filter. The five partitioned heaters were switched on/off with some time interval one the other. The surface temperature distribution in the ceramic filter and electric heaters were measured with varying both the electrical power supply to the heaters and the mass flow rate of the air supply from a blower. The higher mass flow rate in the DPF system enhanced the uniformity in the surface temperature distribution of the ceramic filter due to effective convection heat transfer. The flow in the monolith ceramic structure of the DPF move mainly in the axial direction, which could be identified from the surface temperature of the ceramic filter.

• Journal of applied mathematics & informatics
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• v.18 no.1_2
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• pp.393-403
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• 2005

We study the isothermal flow of a dusty viscous incompressible conducting fluid between two types of boundary motions- oscillatory and non-oscillatory, under the influence of gravitational force. Within the frame work of some physically realistic approximations and suitable boundary conditions, closed form solutions were obtained for the velocity profiles and the skin friction of the particulate flow. These results show that for a constant pressure gradient, only the velocity profile of the fluid and the skin friction are unaffected by gravity, while magnetic field is seen to affect both the fluid, particle velocities and the skin friction. Thus, our results are extension of previous results in literature, and graphical demonstration of some these solutions have been presented.

• Journal of the Korean Society of Combustion
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• v.10 no.4
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• pp.10-17
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• 2005

Sustaining of flame stability of the burner installed in Dielsel exhaust pipe is very difficult because of steep fluctuation of pressure and flow rate. A burner for DPF (Diesel Particulate Filter) which clogged by collected soot regeneration has been made of metal fiber for the purpose of realization of flame stability even in unfavorable condition of Diesel engine exhaust. Flame stability of the metal fiber burner has been investigated in various condition of engine operation. It has been identified that metal fiber burner with liner which has swirl guide vane presents excellent flame stability even in the higher engine revolutions than 3000rpm and sudden variation. The results offer the possibility of development of full flow burner system for DPF regeneration.

• Journal of Institute of Convergence Technology
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• v.1 no.1
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• pp.41-47
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• 2011

With the world-wide demand on the emission minimization, the needs on the diesel aftertreatment devices with high efficiency are also increasing. In order to effectively develop or design a high-performance diesel particulate filter, a clear understanding on the deposition and regeneration mechanism is required. In the present study, a theory on the lumped parameter model for wall-flow type diesel particulate filters is described focusing on the deposition efficiency, pressure drop inside the filter. The fourth order explicit Runge-Kutta method is utilized for the mass flow rate computation. Engine operation modes with controlled and uncontrolled regeneration options are selected. The computational lumped parameter model is validated by comparing the computed results with the measured data.

• Membrane Journal
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• v.8 no.4
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• pp.191-202
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• 1998

The emission standards for diesel particulates have been continued to become tighter. This article reviews the pore and how to filtering characteristics and how to design the ceramic honeycomb filter which is generally used for diesel particulate filter. And the properties and fabrication methods of other particulate filters, i.e. ceramic fiber candle filter, ceramic foam filter, ceramic cross-flow filter and metal filter, are presented in this review. The results show that though the various filters have been developed and tested in the field, the more efforts are needed for the commercilaization of the diesel particulate filter.

• Journal of the korean Society of Automotive Engineers
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• v.9 no.1
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• pp.40-48
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• 1987

A Mini-Dilution Tunnel is described as a scaled down comparision of a Standard Tunnel. The paper presents the result of experimental investigations on measuring the particulate emission of a diesel engine in a Mini and a Standard Dilution Tunnel. The result offers a contribution to understanding about the influence of several parameters including dilution ratios, mixture temperatures, mixture conditions, filter temperatures, and flow conditions. In the experiment either increasing the filter temperature and mixture temperature at a fixed dilution ratio or increasing the dilution ratio at a fixed filter temperature and mixture temperature resulted in a decrease in the total particulate mass. These changes in total particulate mass were attributed to the changes in the soluble organic fraction of the particulate sample. Also, mass differences between the Mini and the Standard Dilution Tunnel for the same engine conditions were within approximately 15% of each other.

• Clean Technology
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• v.26 no.1
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• pp.22-29
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• 2020

Recently, as the fine dust is increased and the emission regulations of diesel engines have been tightened, interest in diesel soot filtration devices has rapidly increased. There is specifically a demand for the technological development of higher diesel exhaust gas after-treatment device efficiency. As part of this, many studies were conducted to increase exhaust gas treatment efficiency by improving the flow uniformity of the exhaust gas in the diesel particulate filter (DPF) and reducing the pressure drop between the inlet and the outlet of DPF. In this study, the effects of pressure drop by the flow rate and temperature of exhaust gas, DPF I/O ratio, Ash, and PM amount in diesel reduction device were simulated via a 12" diameter DPF and diesel oxidation catalyst (DOC) using ANSYS Fluent. As the flow rate and temperature decreased, the pressure drop decreased, whereas the PM amount affected the pressure drop more than the ash amount and the pressure drop was lower in anisotropic DPF than isotropic DPF. In the case of DPF flow uniformity, it was constant regardless of the various variables of DPF. In ESC and ETC conditions, the filtration efficiency for PM was similar regardless of anisotropic and isotropic DPF, but the filtration efficiency for PN (particle number) was higher in anisotropic DPF than isotropic DPF.