• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.341-346
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• 2004

A low NPSH and high pressure fuel pump has been designed for a turbopump system. The fuel pump has an axial inducer and a centrifugal impeller. A meanline method has been established for the preliminary design and performance prediction of pumps at design or off-design points. KeRC carried out a model testing of the fuel pump with water as a working fluid at the reduced speed. Predicted performances by the method are shown to be in good agreement with experimental results for cavitating and non-cavitating conditions. The established meanline method can be used for the performance prediction and preliminary design of high speed pumps which have a inducer, impeller and volute. In the current study, the three dimensional viscous flow in the fuel pump was investigated through numerical computation. A modified design of the fuel pun was generated to improve pump performance by utilizing CFD results. The modified fuel pump was experimentally tested by ROTEM and KARI. The measured non-cavitating and cavitating performance showed a good agreement with designed performance.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.14 no.4
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• pp.41-48
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• 2005

In recent years, the need for multi-stage gear drives which highly reduce output speed has been increased. However, the design of multi-stage gear drives has been carried out by a limited number of experts. The consideration for the direction of input and output axes also makes their design very difficult. The purpose of this study is to develop an algorithm for automatically generating complex multi-stage gear drives and to implement a design supporting system for multi-stage gear drives. There are 4 stages in the proposed algorithm, and major design parameters, such as the direction of input and output axes, reduction ratio, etc. are set up in the first stage. In the second stage, all mechanisms are generated, and various rules are applied to select feasible mechanisms. In the third stage, the gear ratio of each stage is divided from total gear ratio. Next, the specifications of gears for feasible mechanisms are calculated and their bending strength and surface durability are estimated. In the forth stage, appraised indexes are calculated and provided to support the estimation of the generated gear drives.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1993.04a
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• pp.79-85
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• 1993

An integrated structural design system can define and process complex design information that occurs in each of the design stages for flexible cooperation. It can also reduce human error on sequential design steps: preliminary design, analysis and detailed design. Therefore, it's very important to have consistent semantic expression and procedure for structural design information that has complex relationships. In this study, we introduce the object-oriented concepts and object-oriented database thechnique that provides high level semantic expression in order to develop an integrated structural design system.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2002.10a
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• pp.16-16
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• 2002

• The Journal of Aerospace Industry
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• s.25
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• pp.77-101
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• 1992

• Proceedings of the Korean Nuclear Society Conference
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• 2003.05a
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• pp.126-126
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• 2003

• Proceedings of the Korean Nuclear Society Conference
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• 1998.10a
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• pp.43-43
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• 1998

• Proceedings of the Korean Nuclear Society Conference
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• 2001.10a
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• pp.240-240
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• 2001

• Proceedings of the Korean Nuclear Society Conference
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• 1999.05a
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• pp.374-374
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• 1999

• International Journal of Precision Engineering and Manufacturing
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• v.2 no.2
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• pp.65-72
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• 2001

The design of multi-stage gear drives is a time-consuming process, since on includes more complicated problems, which are not considered in the design of single-stage gear drives. The designer has th determine the number of reduction stages and the gear ratios of each reduction state. In addition, the design problems include not only the dimensional design but also the configuration design of gear drive elements. There is no definite rule and principle for these types of design problems. Thus the design practices largely depend on the sense and the experiences of the designer , and consequently result in undesirable design solution. We propose a new generalized design algorithm to support the designer at the preliminary design phase of multi-stage gear drives. The proposed design algorithm automates the design process by integrating the dimensional design and the configuration design process. The algorithm consists of four steps. In the first step, a designer determines the number of reduction stage. In the second step. gear ratios se chosen by using the random search method. In the third step, the values of basic design parameter are chosen by using the generate and test method. Then, the values of other dimension, such ad pitch diameter, outer diameter, and face width, are calculated for the configuration design in the final step. The strength and durability of a gear is guaranteed by the bending strength and the pitting resistance rating practices by using the AGMA rating formulas. In the final step, the configuration design is carried out b using the simulated annealing algorithm. The positions of gears and shafts are determined to minimize the geometrical volume(size) of a gearbox, while satisfying spatial constraints between them. These steps are carried out iteratively until a desirable solution is acquired. The propose design algorithm has been applied to the preliminary design of four-stage gear drives in order to validate the availability. The design solution have shown considerably good results in both aspects of the dimensional and the configuration design.