• Journal of the Korean Society of Industry Convergence
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• v.12 no.1
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• pp.11-18
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• 2009

The air flow and heat transfer characteristics of an air jet impinging on a pedestal heat source has been investigated numerically to examine the effects of geometric parameters such as nozzle-to-pedestal spacing, nozzle diameter and pedestal size. Also, the parameters of Reynolds number, air jet power, supplied heat and thermal conductivity of pedestal have been studied to reveal how these affect the average Nusselt number. Hence, a two-dimensional turbulent model has been developed and adopted to simulate the fluid flow and heat transfer phenomena numerically. The results obtained from the model show that the nozzle-to-pedestal spacing, relative size of nozzle to pedestal and Reynolds number of air jet have a significant influence on the cooling characteristics of heated pedestal. Furthermore, some useful guidelines could be given to the application of cooling the heated pedestal.

• IEMEK Journal of Embedded Systems and Applications
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• v.13 no.6
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• pp.297-303
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• 2018

Recently, the tasks assigned to surface ship are becoming diverse and important. In this trend, shipboard directional pedestals are widely used for surveillance and electronic warfare because ships are always under angular motion such as rolling, pitching and yawing. To estimate the performance of pedestal, the motion responses of vessel as well as mechanical characteristics of pedestal should be considered. In this study, both the motion responses of vessel which the pedestal will be mounted and the behavior of 3-axis pedestal are considered. Numerical analysis based on potential theory is used to obtained motion characteristics of vessel and then 6-DOF motions of vessel are simulated under operational condition. 1st-order time delay model and LQR control algorithm are used for modeling of pedestal drive model and control model, respectively. By using coordinate transform, the angular motions which the pedestal should compensate are calculated from the vessel's angular motion. Through these M&S methodologies, time history of pedestal behavior and maximum angular error of each pedestal axis are obtained. Overall M&S results show that 3-axis pedestal compensate the angular motion induced by vessel, efficiently.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.546-552
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• 2001

The heat transfer and flow measurements on a pedestal encountered in chip cooling. A uniform wall temperature boundary condition at the plate surface and on a pedestal was created using shroud method. Liquid crystal was used to measure the plate surface temperature. The jet Reynolds number (Re) ranges from 11,000 to 50,000, the dimensionless nozzle-to-surface distance (L/d) from 2 to 10, and the dimensionless pedestal diameter-to-height (H/D) from 0 to 1.0. The results show that the Nusselt number distributions at the near the pedestal exhibit secondary maxima at $r/d{\cong}1.0\;and\;1.5$. The formation of the secondary maxima is attributed to an create in the vortex by the pedestal.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.124-130
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• 2001

The heat transfer and flow measurements were made on a cylindrical pedestal mounted on a flat plate with a turbulent impinging air jet. The heat transfer coefficient distributions on the flat plate were measured using the shroud-transient technique and liquid crystal was used to measure the surface temperature. The jet Reynolds number (Re) is 23,000, the dimensionless nozzle-to-surface distance (L/d) from 2 to 10, the dimensionless pedestal diameter-to-height (H/D) from 0 to 1.5, the dimensionless 2nd pedestal diameter-to-height ($H/D_2$) from 0 to 0.4 and the distance from the stagnation point to 2nd pedestal (p/D). The results show that for H/D = 0.5 to 1.5, the Nusselt number distributions on the plate surface exhibit a maximum between $r/d\;{\cong}\;1.0$ and 1.5. The presence of the pedestal appears to cause the flow separation and reattachment on the plate surface, which results in the maximum heal transfer coefficient. Also, for p/D = 2.5 and $H/D_2$ = 0.3, the local Nusselt number in the region corresponding to $r/d\;{\cong}\;1.1$ was increased up to 50% compared to that for $H/D_2=0$.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.1
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• pp.1-8
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• 2003

The heat transfer and flow measurements on a cylindrical pedestal mounted on a flat surface with a turbulent impinging jet were made. The experiments were made for the jet Reynolds number of Re = 23,000, the dimensionless nozzle-to-surface distance of L/d = 2~10, the dimensionless pedestal height of H/D = 0~1.5. Measurements of the surface temperature and the Nusselt number distributions on the plate surface were made using liquid crystal and shroud-transient technique. Flow measurements involve smoke flow visualization and the wall pressure coefficient. The results show that the wall pressure coefficient sharply decreases along the upper surface of the pedestal. However, the pressure increases when the fluid escapes from the pedestal and then collides on the plate surface. The secondary maxima in the Nusselt numbers occur in the region of 1.0 $\leq$ r/d $\leq$ 1.9. Their values for the case of H/D = 0.5 are maximum 80% higher than those for other cases. The formation of the secondary maxima may be attributed to the reattachment of flow on the plate surface which was separated at the edge of the pedestal.

• Special Issue of the Society of Naval Architects of Korea
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• 2015.09a
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• pp.34-40
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• 2015

The design, procurement and fabrication of FPSO project ordered by Inpex Browse, Ltd. have been currently carried out by DSME(Daewoo Shipbuilding Marine and Engineering Co.). The unit will be installed and operated in the Ichthys field offshore of North-Western Australia and there are the particular design requirements to do with performance on the environment loads corresponding to max. 10,000 years return period wave. Also, the operational life of FPSO has to be over 40 years. With this background, this paper introduces the structural design procedure of crane pedestal foundation operated in north-western Australia offshore. The design of crane pedestal foundation structure is basically based on international design code (i.e. API Spec. 2C), Classification society's rule and project specifications. The design load cases are mainly divided into the crane normal operating conditions and crane stowed conditions according to environment conditions of the offshore with 1-year, 5-year, 10-year, 200-year and 10,000-year return period wave. This design experience for crane pedestal foundation operated in north-western Australia offshore will be useful to do engineering of other offshore crane structures.

• Korean Journal of Heritage: History & Science
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• v.43 no.4
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• pp.56-77
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• 2010

The tortoise pedestal for the memorial monument of Choe Jin-rip(an army officer in the mid-Joseon Period) in Ijo-ri, Naenam-myeon, Gyeongju is known to have been made in 1740. As such, it was originally understood to be a Joseon imitation of a tortoise pedestal made in the Unified Silla Period. The style of the Ijori Tortoise Pedestal differs from other tortoise pedestals dating back to the same period, and bears no resemblance to the Unified Silla pedestals of which it is a copy. Mullu ilgi, a record of the production of the pedestal, explains that the monument was made before the pedestal. Traces show that the two sides of the bottom of the monument were cut off so that it would fit into the smaller space made on the pedestal. It is scarcely conceivable that they made the pedestal and the platform without considering the bottom size of the monument. The record only states that the monument was made at a temple site named Baegundae, without explaining the details of the production process. This leaves some doubt as to whether its production was undertaken systematically. The cloud patterns engraved on this pedestal look similar to the temporal seriation found on the Tortoise Pedestal of the Royal Tomb of King Muyeol and the Seoangni Tortoise Pedestal of Gyeongju. The lotus pattern decorating the square pedestal on the back of the tortoise is one of a number of patterns that were widely used on roof-tiles in the 8th century, the heyday of the Unified Silla Kingdom. The Ijori Tortoise Pedestal, which represents a tortoise moving forward, displays a liveliness the like of which is rarely found in its cousins remaining in Gyeongju. The layout of the patterns in a queue on the tortoise-shell looks much better schematized than those made at an earlier date. It also looks like a more developed form, with the use of space taken into account. Such factors as the style of the patterns, the incongruity between the monument and its pedestal, and what is stated in the historical record indicate that the Ijori Tortoise Pedestal of Gyeongju was made in the mid-8th century(i.e. during the Unified Silla Period), rather than in the Joseon Period(i.e. the 18th century), as an imitation of earlier ones, including changes in the style unique to the Silla Period.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.1
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• pp.95-100
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• 2012

A deck crane is installed on the deck of a ship when there is no adequate facility for loading and unloading in dock or harbor. Deck cranes in Korea have been imported from abroad, and the import-substitution effect will arise if its production can be localized. Now, it is required to suggest the structural design of a deck crane that meet the domestic criterion, considering loading condition. In this study, the structural analysis of a pedestal in the deck crane was peformed by finite element method to investigate the strength requirement. In addition, the structural design of a pedestal was suggested by using ANSYS and VisualDOC. The optimized structure of a pedestal was determined, considering lightweight design.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.5 s.110
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• pp.452-456
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• 2006

The critical speeds and mode shapes are most important to determine the behaviors of rotor in designing rotating machinery. As the capacity and span of turbine-generator increases, the turbine-generator system is composed of many components such as bearings, pedestal, turbine and hood and so on. Also, it is getting flexible and has many critical speeds. Especially, as the characteristics of bearing-pedestal are very complicated, they affect the entire vibration characteristics of turbine-generator system. In this paper, it is observed how to determine the equivalent dynamic stiffness of bearing-pedestal by analytical and experimental method.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.11a
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• pp.263-266
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• 2005

The critical speeds and mode shapes are most important to determine the behaviors of rotor in designing rotating machinery. As the capacity and the span of turbine-generator increases, the turbine-generator system has many components such as bearings, pedestal, turbine and baseplates etc. and it is getting flexible and has many critical speeds. Especially, the characteristics of bearing-pedestal are very complicated and then they affect the entire vibration characteristics of turbine-generator system. In this paper, it is observed how to determine the equivalent dynamic stiffness of bearing-pedestal by analytic and experimental method.