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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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The KSFM Journal of Fluid Machinery
Journal Basic Information
Journal DOI :
Korean Fluid Machinery Association
Editor in Chief :
Volume & Issues
Volume 4, Issue 4 - Dec 2001
Volume 4, Issue 3 - Sep 2001
Volume 4, Issue 2 - Jun 2001
Volume 4, Issue 1 - Mar 2001
Selecting the target year
Heat Transfer in Rotating Duct with
Choi, Chung ; Lee, Sei Young ; Won, Jung Ho ; Cho, Hyung Hee ; Park, Byung kyu ;
The KSFM Journal of Fluid Machinery, volume 4, issue 3, 2001, Pages 7~13
The present study investigates convective heat/mass transfer and flow characteristics inside a cooling passage of rotating gas-turbine blades. The rotating duct has staggered ribs with
attack angle, which are attached on leading and trailing surfaces. Naphthalene sublimation technique is employed to determine detailed local heat transfer coefficients using the heat and mass transfer analogy. Additional numerical calculations are conducted to analyze the flow patterns in the cooling passage. The present experiments employ two-surface heating conditions in the rotating duct because the exposed surfaces to hot gas stream are pressure and suction side surfaces in the middle passages of an actual gas-turbine blade. Secondary flows are generated by Coriolis and centrifugal forces in the spanwise and streamwise directions. The ribs attached on the walls disturb the mainflow resulting in recirculation and secondary flows near the ribbed wall. The local heat transfer and flow patterns in the passage are changed significantly according to rib configurations and duct rotation speeds. Therefore, the geometry and arrangement of the ribs are important for the advantageous cooling performance. The experimental results show that the ribs enhance the heat transfer more than
from that of the smooth duct. The duct rotation generates the heat transfer discrepancy between the leading and trailing walls due to the secondary flows induced by the Coriolis force. The overal heat transfer pattern on the leading and trailing walls for the first and second passes are depended on the rotating speed, but the local heat transfer trend is affected mainly by the rib arrangements.
Numerical Analysis of the 3-D Flow Field in a Globe Valve Trim under High Pressure Drop
Yoon, Joon-Yong ; Byun, Sung-Joon ; Yang, Jae-Mo ; Lee, Do-Hyung ;
The KSFM Journal of Fluid Machinery, volume 4, issue 3, 2001, Pages 14~20
Numerical analysis of the three dimensional turbulent flow field in a complex valve trim is carried out to confirm the possibility whether this simulation tool can be used as a design tool or not. The simulation of the incompressible flow in a glove valve is performed by using the commercial code. CFD-ACEA utilizes the finite volume approach as a discretization scheme, and the pressure-velocity coupling is made from SIMPLEC algorithm in it. Four flow cases of the control valve are investigated, and the valve flow coefficient for each case is compared with the experimental data. Simulation results show a good agreement with the experiments, and it is observed that the cavitation model improves the simulation results.
Effects of Vaned Diffuser Shapes on the Flowfields of a Small-Size Turbo-Compressor
Kim, H.-S. ; Kim, Youn J. ; Kim, C.-S. ;
The KSFM Journal of Fluid Machinery, volume 4, issue 3, 2001, Pages 21~28
The effects of diffuser shapes on the flowfields of a small-size turbo-compressor have been investigated numerically and experimentally. The optimal design of elements shapes is important to develop the high efficiency turbo-compressor. Typical range of rotating speed for a small-size turbo-compressor is 40,000-70,000rpm. Numerical analyses were conducted to the rectangular and conical shapes of diffuser Three-dimensional, steady and viscous governing equations were solved by SIMPLE algorithm. To confirm the numerical results, the experimental measurements for the static pressure and temperature at the inlet and outlet boundaries were performed. Comparisons of these results were done, and the reasonable agreements were acquired.
Leakage and Rotordynamic Analysis of High Pressure Floating Ring Seal in Turbo Pump
Ha, Tae Woong ; Lee, Yong-Bok ; Kim, Chang-Ho ;
The KSFM Journal of Fluid Machinery, volume 4, issue 3, 2001, Pages 29~38
The floating ring seal has the ability of minimizing clearance without the rubbing phenomenon. It is often used in the turbo pump units of liquid rocket engines due to its superior leakage performance. The exact prediction of the lock-up position of the floating ring, the leakage performance, and the rotordynamic coefficients of the seal is necessary to evaluate the rotordynamic performance of the turbo pump unit. The governing equations(which are based on the Bulk-flow Model) we solved by the Fast Fourier Transform method. The lock-up position, leakage flow rate, and rotordynamic coefficients are evaluated according to the geometric parameters of the floating ring seal.
Pressure Distributions of a Screw-type Centrifugal Pump Operating in Air-Water Two-Phase Flow
Kim, You-Taek ; Choi, Min-Seon ; Lee, Young-Ho ;
The KSFM Journal of Fluid Machinery, volume 4, issue 3, 2001, Pages 39~45
It is reported recently that the pump head deterioration near the best efficiency point, from single-phase flow to the choke due to air entrainment became less in a screw-type centrifugal pump than in a general centrifugal pump. Moreover, at a narrow tip clearance, the pump head became partially higher in two-phase flow than that in single-phase flow. However, the internal pressure fluctuations on this pump due to air entrainment have not been studied yet. For that reason, we have examined the influences of void fraction, flow coefficient and impeller tip clearance on pressure fluctuations in the casing. The void fraction became larger, the influence of tip clearance on pressure distribution became less.
Axial Turbine Performance Evaluation in a Rotating Facility
Yoon, Yong-Sang ; Song, Seung-Jin ; Kim, Hong-Won ; Cho, Sung-Hee ;
The KSFM Journal of Fluid Machinery, volume 4, issue 3, 2001, Pages 46~52
This paper describes a turbine test program conducted at Seoul National University(SNU). To measure blades' aerodynamic performance, either linear(2-Dimensional) or annular(3-Dimensional) cascades are often used. However, neither cascade can consider effects such as those due to rotation or rotor-stator interaction. Therefore, a rotating test facility for axial turbines has been designed and built at SNU, and its description is given in this paper. The results from an axial turbine performance test are presented. At the design point, the measured efficiency agrees with the efficiency predicted by a meanline analysis. At off design points, however, the measured and predicted efficiencies diverge. The most likely cause is hypothesized to be the inaccuracy of correlations used in the meanline analysis at off design points.
A Study on the Characteristics of Two-Step-Flow-Control Fluidic Device
Cho, Bong-Hyun ; Bae, Yoon-Yeong ; Park, Jong-Kyun ; Yoo, Seong-Yeon ;
The KSFM Journal of Fluid Machinery, volume 4, issue 3, 2001, Pages 53~61
Vortex type Fluidic Device(FD) which is installed at the bottom of Safety Injection Tank(SIT) controls the discharge flow rate from the tank. In case of loss of coolant accident the injection water flows into primary system in two steps; initial high flow rate for certain period of time and subsequent low flow rate. By two-step control of the discharge flow rate, FD can ensure the effective use of water in the tank. A small-scale FD has been tested to obtain a required flow characteristics maintaining full pressure and height of prototype, which are the major contributing parameters. Through the testing of many different arrangements of internal geometry of FD, most appropriate one was selected and its performance data was obtained. As characteristics of FD, time dependent Euler number, flow rate and pressure are presented and discussed. Also a method to predict the full size FD is presented.
Technique of Medern Wind Power Generation
Kim, Jeong-Hwan ; Kim, Yoon-Hae ; Lee, Young-Ho ;
The KSFM Journal of Fluid Machinery, volume 4, issue 3, 2001, Pages 62~77
The modern wind turbines are widely used as important natural energy sources for the electric generation in western countries and some Asian nations. They are commercially matured and progressive and clear policy for the more development with higher technical purposes is maintained throughout the world. Modern wind turbines produce nearly 2000 kW output in their largest sizes and this trend increases up to more powerful power and ultimate utilization of wind energy favoured by clean natural energy. This article has the points of reviewing the states of the art of modern wind turbines with their present technical directions toward next generation version. Some descriptionsare given for easy understanding of the turbine components and related fluid mechanics concerned. The general outlines of policy taken over some countries are also introduced.
CFD Analysis for Turbomachinery
The KSFM Journal of Fluid Machinery, volume 4, issue 3, 2001, Pages 78~89
극저온 스터링 냉동기용 선형압축기 개발
The KSFM Journal of Fluid Machinery, volume 4, issue 3, 2001, Pages 90~95
스크롤 압축기 기술
The KSFM Journal of Fluid Machinery, volume 4, issue 3, 2001, Pages 96~105
대체냉매를 사용한 스크루 압축기의 성능에 관한 연구
The KSFM Journal of Fluid Machinery, volume 4, issue 3, 2001, Pages 106~109
터보냉동기용 원심압축기의 설계
The KSFM Journal of Fluid Machinery, volume 4, issue 3, 2001, Pages 110~118
HVAC 시스템의 소음원 및 소음 제어
The KSFM Journal of Fluid Machinery, volume 4, issue 3, 2001, Pages 119~126