• Proceedings of the Korean Geotechical Society Conference
• /
• 2006.03a
• /
• pp.316-321
• /
• 2006

The Prouductivity of pump dredger varies very much depend on soil conditions is one of the main factors affecting construction period. Therefore the acculate evaluation of dredging capability of pump dredger considering soil conditions is a main task in dredging projects. After assesing the results of pump dredging on several Gwangyang port projects, some data of Japan standard for pump dredger are similar to those of actual results and a pump dredging capability table is prepared for future evaluation purposes.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.06a
• /
• pp.322-322
• /
• 2010

In this paper, we propose a novel type valveless micro-pump that uses extensional vibration mode of traveling wave as a volume transporting means for solving some problems about check valves, essential parts of usual pumps. The proposed pump consists of two piezoelectric ceramic rings and a metal body located in the middle of them respectively. Because the drift of bended surface that results from the traveling wave excitation controls the fluid flow, check valves are not needed in this pump model. In accordance with the variation of the pump body dimension, we analyzed the vibration displacement characteristics of pump model, determined the optimal design condition, fabricated the prototype pump from the analysis results and evaluated its efficiency.

• The KSFM Journal of Fluid Machinery
• /
• v.4 no.4 s.13
• /
• pp.7-15
• /
• 2001

Flow analysis was carried out for a double-suction centrifugal pump. Impeller-only models and a full pump model were used to simulate the velocity field and the pressure field of the pump. Heads and efficiencies were calculated with flow rates in order to obtain general performance of the pump. The calculation results were compared to the experimental data, and satisfactory results were obtained. Thus, it may be said that the CFD serves as a useful tool for pump designs.

• The KSFM Journal of Fluid Machinery
• /
• v.10 no.4
• /
• pp.21-28
• /
• 2007

The ratio of disk friction loss in a centrifugal pump is very large for the total pump loss in the range of very low specific speed. Therefore, impeller radius should be shortened to increase the pump efficiency because the disk friction loss is proportional to the fifth power of impeller radius. In order to compensate the decreased head by the shortened impeller radius, vane angle at impeller outlet should be increased. However, as the vane angle at impeller outlet becomes larger, performance instability occurs at low flow rate regions. In this study, J-Groove is adopted to suppress the performance instability and detailed examination is performed for the influence of the J-Groove on the pump performance. The results show that J-Groove gives good effect on the suppression of performance instability. Moreover, as J-Groove increases pump head considerably, the pump size can be smaller for head requirements.

• International Journal of Fluid Machinery and Systems
• /
• v.1 no.1
• /
• pp.86-91
• /
• 2008

The effects of the diffuser vane on the performances of the multistage centrifugal pump were investigated experimentally, taking account of the interactions among the diffuser vane, the return vane, and the next stage impeller. It is very important to match well the diffuser vane with the return vane, for improving the hydraulic efficiency of the pump. The efficiency may be more improved by making the cross-sectional area of the channel from the diffuser vane outlet to the return vane inlet larger, as much as possible.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.20 no.5
• /
• pp.612-617
• /
• 2011

The comfort and quietness of vehicle has been improved greatly due to the development of technology in automobile industry. Some of noise reductions, for example, are driven by the improvement in the power-train system. Due to better in all performance, it is required to reduce more noise in automobile components. One of them is related to the fuel pump system including a pump and a tank. Therefore, this study is focused on investigating the characteristics of fuel pump and fuel tank first, and then comparing the data before and after installation of fuel pump system in a testing vehicle. Additionally, the measured data will be analyzed to identify the problems and provide knowledge to reduce the level of noise and vibration in fuel pump system.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.32 no.4
• /
• pp.275-282
• /
• 2008

In Korea, air source heat pump system is less efficient than conventional heat source facilities, because the air temperature in winter season is so low that COP of air source heat pump system drops below 3.0. Therefore, the study on the application of heat pump heating and cooling systems is crucial for the efficient popularization of heat pump. In this work, we present the dynamic analysis of energy consumption for the large hospital building by heat resistance-capacitance method. The system simulation of water storage air source heat pump is additionally performed by changing sizes and locations of the hospital building. The computed results show that energy cost of water storage air source heat pump is low, so it is more economical than absorption chiller & heater.

• Journal of Advanced Marine Engineering and Technology
• /
• v.31 no.8
• /
• pp.1035-1041
• /
• 2007

An improvement of driving motor burning damages on a couplingless type warship fire pump is studied. The pump consists of an induction motor a pump-motor shaft and a volute type impeller. The burning damage had occured by changing the material of the pump-motor shaft from carbon steel(SM 45C) to stainless steel(STS 316) for improving anti-corrision properity in sea water. It is shown that a material change on the pump-motor shaft can reduce the efficiency of driving motor and may cause motor burning in the process of pump development stage. This kind of motor burning problem can be solved by increasing the efficiency of the motor and changing the geometry of the inner parts.

• Proceedings of the KSME Conference
• /
• 2000.04b
• /
• pp.555-560
• /
• 2000

An experimental study on pumping characteristics of various turbo-type drag pumps is purformed. The inlet pressures are measured for various outlet pressures of the test pump. The maximum compression ratios for nitrogen are 100,000(Disk-type drag pump+ turbo molecular pump), 10000(Helical-type drag pump+turbo molecular pump), 850 (Helical-type drag pump), 100(disk-type drag pump).

• 유체기계공업학회:학술대회논문집
• /
• 2005.12a
• /
• pp.645-649
• /
• 2005

In this study, redesign of a vaporizer sea-water pump has been carried out using computational fluid dynamics. The flow field of the specified pump model is simulated and analyzed. In the flow analysis full pump model has been used, and multi-block grids are employed to solve the governing equations. In order to improve pump efficiency, systematic redesign has been performed to remove the flow recirculation near the hub of the diffuser vanes. The modified model shows about 4 % improvement in pump efficiency compared to the given model.