• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.594-597
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• 2009

The mixing characteristics of pylon injection in a Scramjet combustor and effects of film cooling to protect pylon from air-heating. Three-dimensional Navier-Stokes equations with $k-{\omega}$ SST turbulence model were used. Fuel hydrogen and air were considered as coolants. There were remarkable improvements of penetration and mixing rate with the pylon injection. There also over-heating on the front surface of pylon without film cooling. The coolant injected parallel to the front surface of the pylon protect the pylon from over-heating.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.1
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• pp.20-28
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• 2010

The mixing characteristics of pylon injection in a Scramjet combustor and effects of film cooling to protect pylon from air-heating were investigated. Three-dimensional Navier-Stokes equations with $k-{\omega}$ SST turbulence model were used. Fuel hydrogen and air were considered as coolants. There were remarkable improvements of penetration and mixing rate with the pylon injection. There was also over-heating on the front surface of the pylon without film cooling. The coolant injected parallel to the front surface of the pylon protects the pylon from over-heating.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.5
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• pp.10-18
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• 2011

A new film cooling method to protect the pylon injector from aerodynamic heating for a scramjet combustor is proposed and verified with numerical methods. The conditions for the Mach 8 flight at an altitude of 35km are considered. Air is considered as a coolant. Three-dimensional Navier-Stokes equations with $k-{\omega}$ SST turbulence model are used. A downward injection of coolant from the top of the pylon gives higher cooling effects with less mass flow rate of coolant than the upward coolant injection from bottom of the pylon. Also, the downward injection shows little flow separation due to the favorable pressure gradient and does not disturb the flowfields near pylon injector, which results in reduction of pressure losses.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.2
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• pp.120-125
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• 2021

Phylon molds are widely used for injection molding of foams used in shoe outsoles. Injection pylon molds are usually prepared by first casting the aluminum alloy and then applying an anodized coating to improve durability. This study was carried out to examine the durability of aluminum phylon molds. The aluminum materials used in this study were A771, A6061, and AC4C, and their mechanical properties were compared. Specimens for anodic oxidation tests were prepared with coating thicknesses of approximately 10 and 40 ㎛. We tried to select the optimum material and coating thickness suitable for fabricating phylon injection molds. Among the three materials, A6061 exhibited the best tensile, wear, and impact properties. The difference in the wear resistance between the soft- and hard-anodized coatings was insignificant.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.275-278
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• 2002

The recognition of the natural background radiation is important not only for radiological education but also for the promotion of people's scientific view about radiation. We made a "room" on the web showing natural background radiation as part of a VRM (Virtual Radiation Museum). The "room" shows the video images of the tracks of charged particles from natural background radiation, alpha and beta ray track from known sources using a Large Scale Diffusion Cloud Chamber. The purpose of this study is to make clear the origin of a kind of track (named A-track) which is thick and easy to recognize with the length less than several cm in the cloud chamber, and to make numerical explanation of its counting rate. The study was carried out using a Large Scale Diffusion Cloud Chamber (Phywe, Germany) installed in the Niigata Science Museum. The Model RNC (Pylon Electronics, Canada) was used as Rn-222 source. Ra-226 activity in RNC was 111.6 Bq calibrated with NIST protocol. Rn-222 gas was injected into the cloud chamber. Continuous video recording with use of Digital Handycam (SONY, Japan) was carried out for 360 min. after injection of Rn-222 gas. The number of alpha-ray track (alpha track) in the video images was analyzed. The growth and decay curve of the total activity of Rn-222 and its alpha emitting progeny were calculated and compared with the count of the alpha tracks. As a result the alpha tracks formed by Rn-222 injection resemble A-Tracks. The relationship between A-track in the cloud chamber and atmospheric Rn is discussed.