Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
The KSFM Journal of Fluid Machinery
Journal Basic Information
Journal DOI :
Korean Fluid Machinery Association
Editor in Chief :
Volume & Issues
Volume 12, Issue 6 - Dec 2009
Volume 12, Issue 5 - Oct 2009
Volume 12, Issue 4 - Aug 2009
Volume 12, Issue 3 - Jun 2009
Volume 12, Issue 2 - Apr 2009
Volume 12, Issue 1 - Feb 2009
Selecting the target year
A Numerical Study on the Flow Characteristics of Side-suction Inlet Geometry for Centrifugal Pump
Kim, Sung ; Choi, Young-Seok ; Lee, Kyoung-Yong ;
The KSFM Journal of Fluid Machinery, volume 12, issue 6, 2009, Pages 7~12
DOI : 10.5293/KFMA.2009.12.6.007
This paper presents a numerical study on the design of side-suction inlet geometry which is used for multi stage centrifugal pumps or inline centrifugal pumps. In order to achieve an optimum inlet geometry and to explain the interactions between the different geometric configurations, the three dimensional computational fluid dynamics and the design of experiment methods have been applied. Geometric design variables describing the cross sectional area distribution through the inlet were selected. The objective functions are defined as the non-uniformity of the velocity distribution at the passage exit which is just in front of the impeller eyes. From the 2k factorial design results, the most important design variable was found and the performance of the side suction inlet was improved compared to the base line shape.
Effect of Nozzle Geometry on the Suction Flow Rate in a Ejector
Kim, Yoo-Jun ; Park, Joung-Woo ; Seo, Lee-Soo ;
The KSFM Journal of Fluid Machinery, volume 12, issue 6, 2009, Pages 13~17
DOI : 10.5293/KFMA.2009.12.6.013
Ejector is an equipment devised for making use of the low pressure occurring from the fast fluid injection and it is a transportation equipment which can obtain vacuum using the kinetic energy of the fluid. This ejector system is, nowadays, widely used for construction machinery, heavy equipments, the cooling and ventilation of electronic devices and for the various fluid transportation and pumps. In this study, it is attempted to perform a numerical analysis and an experiment to find out the characteristics of fluid quantity, velocity and the pressure distribution of the induction pipe by changing the length and the radius ratio of the nozzle of ejector. From the results, it is investigated that the distributions of velocity and pressure of induction pipe attached are changing with the length and the radius ratio of the nozzle. In addition, it is shown that for the small and large ejector, the efficiency is the maximum when the length of the nozzle arrived to the neck of the ejector, however, if it is installed at below or above the neck the efficiency is rather decreased.
Effect of Swirl Flow Disturbance on Uncertainty of Flow Rate Measurement by Venturi
Lee, Jung-Ho ; Yoon, Seok-Ho ; Yu, Cheong-Hwan ; Park, Sang-Jin ; Chung, Chang-Hwan ;
The KSFM Journal of Fluid Machinery, volume 12, issue 6, 2009, Pages 18~25
DOI : 10.5293/KFMA.2009.12.6.018
Venturi has long been an attractive method of measuring flow rate in a variety of engineering applications since pressure loss is relatively small compared with other measuring methods. The current study focuses on making detailed uncertainty estimations as the upstream flow disturbance affects uncertainty levels of the flow rate measurement. Upstream flow disturbance can be determined by 9 different swirl generators. Measurement uncertainty of flow rate has been estimated by a quantitative uncertainty analysis which is based on the ANSI/ASME PTC 19.1-2005 standard. The results of flow rate uncertainty analysis show that the case with systematic error has higher than that without systematic error. Especially the result with systematic error exhibits that the uncertainty of flow rate was gradually increased by swirl flow disturbance. The uncertainty of flow rate measurement can be mainly affected by differential pressure and discharge coefficient. Flow disturbance can be also reduced by increasing of the upstream straight length of Venturi.
Development of Load apparatus for Motor
Lim, Byung-Ju ; Park, Chang-Dae ;
The KSFM Journal of Fluid Machinery, volume 12, issue 6, 2009, Pages 26~32
DOI : 10.5293/KFMA.2009.12.6.026
We have constructed loading apparatuses to electrical motor with a powder brake and a oil pump for load test of a several ten kilowatt-motor and performed load test with two motors. On operating the loading apparatus with a oil pump, temperature of the oil may excessively increase and fail to operate due to dynamic energy loss of equipment in oil loop. In order to control the oil temperature, factors of the energy loss were analyzed and the quantitative loss was calculated. Load tests of motors with two loading apparatuses constructed were successfully performed and strengths of each apparatus come out on operating.
Bearing Pad Temperature Change Depending on the Preload of Vertical Journal Guide Bearing
Kim, Jun-Sung ; Kim, Du-Young ; Kim, Dong-Kwan ; Park, Sang-Ho ;
The KSFM Journal of Fluid Machinery, volume 12, issue 6, 2009, Pages 33~40
DOI : 10.5293/KFMA.2009.12.6.033
The temperature of vertical pump bearing metal in the pumped storage power plant has been high enough to shutdown the unit. Attempts such as decreasing the oil supply temperature, increasing the bearing oil gap etc. were performed to resolve the problem, but the issue was not resolved. Finally, the high bearing metal temperature was corrected by adjusting the bearing preload. The preload is formed by the oil wedge between the journal surface and bearing pad surface and the degree of preload is determined by the machined radial clearance, assembled radial clearance, rotor journal diameter etc. This paper focuses on the analysis of the preload depending on the bearing parameters and the result of the modification of the bearing following the analysis. The bearing metal temperature dropped as much as
which was similar as expected by software calculation. But the shaft vibration could increase when the assembled radial clearance is excessive. So, the adjustment of the bearing preload for the tilting pad type journal bearing should be carefully performed.
Expanding the MCS of Refinery Process Compressor through Operating-Speed Balancing at 10,500 rpm
Lee, An-Sung ; Kim, Byung-Ok ;
The KSFM Journal of Fluid Machinery, volume 12, issue 6, 2009, Pages 41~46
DOI : 10.5293/KFMA.2009.12.6.041
This paper deals with the operating-speed (high-speed) balancing of a refinery gasoline HDS (hydrodesulfurization) process recycle-gas 8-stages compressor rotor. A low-speed balancing condition of the rotor was measured as maintaining the G2.5 level. But an inspection run of operating-speed balancing condition, using tilting-pad journal bearings of actual use, showed that while it could be continuously-operated safely at a rated speed of 10,500 rpm, the rotor would not be able to run over 11,000 rpm as the vibration increased very sharply, approaching 11,000 rpm. In order to cure that a series of operating-speed balancing, which first calculated balance correction-weights by applying the influence coefficient measured and calculated at 10,500 rpm and then implemented correction works, was carried-out. The final operating-speed balancing results showed that the vibrations at the bearing pedestals represented very good levels of 0.2 mm/s by decreasing to as much as the 1/10 of the original vibrations and particularly, even at a targeted maximum continuous operating speed, MCS, of 11,500 rpm the vibrations represented about 1 mm/s, which is the operating-speed balancing vibration specification of API. Therefore, the expansion of MCS was successfully accomplished through the operating-speed balancing.
A Study on the Microbubble Characteristics of Ozone to Improve Dissolution Efficiency
Kim, Jin-Hoon ; Park, Jong-Ho ;
The KSFM Journal of Fluid Machinery, volume 12, issue 6, 2009, Pages 47~53
DOI : 10.5293/KFMA.2009.12.6.047
Ozone is a strong oxidant and a powerful disinfectant. In general, it has been used in drinking water treatment during last 100years. Ozone dissolution features are defined by the two categories of ozone contactors, bubble-diffuser and sidestream ozone contactor. Currently, sidestream-injection systems are gaining in popularity but operating cost might be slightly higher. Sidestream ozone system dissolve ozone into a sidestream flow via an injection setup or in the main process flow stream in some sidestream arrangements. The sidestream flow is subsequently mixed with the main process flow stream, which is directed to a reation tank or pipeline for oxidation and disinfection reactions. The purpose of this study is to suggest optimal operating pressure, to figure out the static-mixer effect and to understand the microbubble characteristics of ozone to improve dissolution efficiency.