• Transactions of the Korean hydrogen and new energy society
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• v.21 no.5
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• pp.383-389
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• 2010

Co-B, Co-P-B, Co-Ni-B and Co-Ni-P-B catalysts supported on Ni foam were prepared using electroless plating in the present study. The surface morphology of the catalysts/Ni foam was observed using SEM and EDS analysis. The Co-Ni-P-B/Ni foam catalyst showed the superior performance on hydrogen generation due to the uniform formation of catalyst particles on the Ni foam surface. The characteristics of hydrogen generation with Co-Ni-P-B/Ni foam catalyst was investigated at the variety of $NaBH_4$ and NaOH concentrations. Durability test was performed, resulting in the stable hydrogen generation for 6 hours.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.10a
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• pp.297-300
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• 2001

Physical modeling technique is applied to investigate foam generation in molten aluminum. By using room temperature water with specially designed equipment, the effects of stirrer type, fluid viscosity(glycerine added to water) and stirring velocity on foam generation behaviors are intensively analysed The distribution and size of bubbles varied with each process parameters but the most important parameters are stirring velocity and fluid viscosity. The results obtained from physical simulation have been confirmed by actual aluminum foam generation experiment at various process variables.

• International Journal of Concrete Structures and Materials
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• v.4 no.1
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• pp.55-62
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• 2010

The performance evaluation of a sodium lauryl sulfate to qualify as a foaming agent is presented in this paper. When new surfactants are used a systematic study of production parameters on the foam characteristics needs to be undertaken unlike proprietary foaming agents and foam generator for which manufacturer has predefined the parameters. The relative influence of the foam parameters and optimization of factors were carried out through a systematic experiment design. The foam production parameters namely foam generation pressure and dilution ratio of foaming agents are observed to have significant effect on all foam characteristics with the exception of foam output rate on which only foam generation pressure has influence. The foam with good initial foam density need not necessarily be stable foam. The optimum levels of foam production parameters are determined for the surfactant Sodium lauryl sulfate which can be used to produce stable foam for foam concrete production.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.3
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• pp.179-185
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• 2004

The characteristics of foam generation were assessed for freshwater and seawater using a foam generator. Both in freshwater and seawater, the height of the foam layer increased with initial protein concentrations. The height of the foam layer also increased with pore size of the air distributor. The optimum superficial air velocities (SAV) in freshwater and seawater were 0.84 cm/sec and 0.6 cm/sec, respectively. The height of the foam layer was the highest in pH 3 in freshwater and in the region of pH 5-7 in seawater. The height of the foam layer increased with $NaHCO_3$ concentration in freshwater, and $NaHCO_3$ concentration had little effect in seawater. Removal efficiencies of total suspended solid (TSS) and turbidity decreased with an increase of initial protein concentrations in a batch foam separator both in freshwater and seawater.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1570-1575
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• 2004

In order to evaluate the performance of fire-fighting agents used to protect structures from heat and fire damages, the thermal characteristics of fire-protection foams are experimentally investigated. The current research focuses on the destruction of a fire-fighting foam subjected to heat radiation. A simple repeatable test for fire-protection foams subjected to fire radiation is developed. This test involves foam generation equipment, a fire source for heat generation, repeatable test procedures, and data acquisition techniques. Results of the experimental procedure indicated that each thermocouple within the foam responded in a similar manner and gradually to a temperature of $15^{\circ}C{\sim}20^{\circ}C$. At this point, each trace generally rises to a temperature of approximately $90^{\circ}C$. The temperature gradient in the foam as time passes increases with increased foam expansion ratio. In addition, it is determined that the temperature gradient along the foam for depth decreases with increased foam expansion ratio.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.1 s.232
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• pp.151-158
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• 2005

A characteristic of discharge for a foam spray nozzle with various parameters was investigated. The discharge patterns from a fire foam spray nozzle are important to evenly spray over a maximum possible floor area. Two parameters of a foam spray nozzle were chosen, and compared with those from the standard one. Also, in order to evaluate the performance of discharged foam agents used to protect structures from heat and fire damages, the thermal characteristics of fire-protection foams were experimentally investigated. A simple repeatable test for fire-protection foams subjected to fire radiation was developed. This test involves foam generation equipment, a fire source for heat generation, and data acquisition techniques. Results show that the bubble size of foam is increased by large inside diameter of orifice or closed air hole, but phenomenon of discharge angle and expansion ratio is opposite. For the case of the open air hole, liquid film of a circular cone discharges with formation, growth, split and fine grain. In case of the closed air hole, a pillar of foam solution discharges with that. Though the temperature gradient in the foam increases with increased foam expansion ratio. it is not change with increased intensity of heat flux.

• Fire Science and Engineering
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• v.22 no.5
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• pp.83-89
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• 2008

Using the high expansion foam generator of ISO 7203-2 which spray 6 liter at 5 bar, foam generation characteristics was studied. Wind flow rate, foam screen, concentration of foam agent solution and concentration of salt of water were varied to find the effect of the parameters on foam generation. Research result showed that expansion ratio of foam was increased with wind flow rate. The expansion ratio of foam in the perforated type standard screen was higher than the wire mesh screen. Expansion ratio and drainage time were increased with increase of foam solution concentration. But a increase of salt concentration in solution showed the decrease of expansion ratio and drainage time.

• Journal of computational fluids engineering
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• v.21 no.2
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• pp.25-31
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• 2016

In this paper, a study on the development of OpenFOAM grid generation program for two-dimensional flow analysis is described. By using the pre-processor(eMEGA) of EDISON_CFD system, grids for OpenFOAM flow calculation were obtained. Resultant two-dimensional grids were used to calculate flow fields by applying simpleFoam, one of the OpenFOAM's popular solvers, and the obtained flow results were compared with theoretical and experimental data available. Also grids generated by present program were compared with grids by a commercial pre-processor Pointwise for the purpose of verification. Verification work includes three cases(single block, O-type single block, and multi block grid), and all results show reasonable matches. According to the current achievement, it can be concluded that OpenFOAM grid can be constructed conveniently by using eMEGA with GUI.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.5
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• pp.509-514
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• 2003

We performed the experiment to determine the effective factors, such as the initial concentration of protein, pore size of air distributor, SAV (superficial air velocity), pH, salts and temperature related to foaming characteristics. The foam height in a foam generator was increased with the increase of the initial protein concentration and the decrease of pore size. As SAV was increased, the foam height was increased, and the optimum SAV was 0.84 cm/sec. The foam height was highest in the acid region and it was increased with the increase of salt concentration of NaCl and $NaHCO_3.$ The removal efficiencies of TSS (total suspended solid) and turbidity decreased with the increase of the initial protein concentration in the batch foam separator.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.29 no.6
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• pp.382-388
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• 2017

This study performed an OpenFOAM-based numerical modeling for simulating performance of wave reduction by a floating vertical plate. Based on the Waves2FOAM library, an internal wave generation and energy dissipation with sponge layers schemes were further implemented. The performance of wave generation and dissipation was first tested with a simple two-dimensional analysis. Then, numerical simulation was carried out with the experimental data of Briggs et al. (2001) for the two regular wave cases. In general, the modeling results agreed well with the experimental data, showing better agreement than the numerical analysis by WAMIT that is included in Briggs et al. (2001).