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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 15, Issue 6 - Dec 2012
Volume 15, Issue 5 - Oct 2012
Volume 15, Issue 4 - Aug 2012
Volume 15, Issue 3 - Jun 2012
Volume 15, Issue 2 - Apr 2012
Volume 15, Issue 1 - Feb 2012
Selecting the target year
Complete Characteristic Curve for a Reactor Coolant Pump
Yoo, IlSu ; Park, MuRyong ; Hwang, SoonChan ; Yoon, EuiSoo ;
The KSFM Journal of Fluid Machinery, volume 15, issue 5, 2012, Pages 5~10
DOI : 10.5293/kfma.2012.15.5.005
An experimental test facility for the complete characteristics of pumps is constructed at KIMM(Korea Institute of Machinery and Materials). All sensors instrumented in test facility for measuring flow rate, pressure, force and moment are in-situ calibrated by primary method. This paper describes the test facility and test technique of the complete characteristics of pumps, together with an experimental test results for a reactor coolant pump which is designed at KIMM for the first time in Korea. The test results for the mixed-flow type pump of
=1.425 are presented by three curves: constant head, torque, and speed.
Optimizing the Manifold Design of a Fuel Cell Stack for Uniform Distribution of Reactant Gases within Fuel Cell Channels
Jo, A-Rae ; Kang, Kyung-Mun ; Oh, Sung-Jin ; Ju, Hyun-Chul ;
The KSFM Journal of Fluid Machinery, volume 15, issue 5, 2012, Pages 11~19
DOI : 10.5293/kfma.2012.15.5.011
The main function of fuel cell manifold is to render reactants distribution as uniform as possible into a fuel cell stack. The purpose of this study is to numerically investigate the effects of stack manifold design on reactants distribution within a fuel cell stack. Four manifold designs with different manifold entrance shapes (expansion or diffuser) and different values of the extra width between the cell outer channel and manifold side wall are considered and applied to the fuel cell stack consisting of 50 cells. Since the fuel cell stack geometry involves several millions of grid points for numerical calculations, a parallel computing methodology is employed to substantially reduce the computational time and overcome the memory requirement. The numerical simulations are carried out and calculated results clearly demonstrate that both the manifold entrance shape and extra width have a substantial influence on manifold performance, controlling the degree of flow separation and entrance length for fully developed flow in the manifold channel. Finally, we suggest the optimum design of fuel cell manifold based on the simulation results.
Experimental Research on the Altitude Performance of an Auxiliary Power Unit for Helicopters
Kim, Chun-Taek ; Cha, Bong-Jun ;
The KSFM Journal of Fluid Machinery, volume 15, issue 5, 2012, Pages 20~26
DOI : 10.5293/kfma.2012.15.5.020
An APU(Auxiliary Power Unit) for helicopters has been developed in Korea and tested at the AETF(altitude engine test facility) in KARI(Korea Aerospace Research Institute) for the purpose of the military qualification. A cell correlation test was performed before the official test, and the results are within the tolerance. The APU has the capability of supplying electric power as well as compressed air to the helicopters. It was tested at bleed extraction conditions, electric power extraction conditions, and maximum continuous concurrent power conditions within the entire helicopter flight envelop. Some special test equipments were implemented for the measurement of air flowrate, electric power and so on. The tests were successfully performed and their results satisfy the requirements of the helicopters.
Performance Analysis of Turbofan Engine for Turbine Cooling Design
Kim, Chun-Taek ; Rhee, Dong-Ho ; Cha, Bong-Jun ;
The KSFM Journal of Fluid Machinery, volume 15, issue 5, 2012, Pages 27~31
DOI : 10.5293/kfma.2012.15.5.027
Turbine inlet temperature is steadily increasing to achieve high specific thrust and efficiency of gas turbine engines. Turbine cooling technology is essential to increase turbine inlet temperature. For this study, a small or medium sized aircraft engine of 10,000 lbf class with the turbine inlet temperature of
, the engine overall pressure ratio of 32.2, and the bypass ratio of 5 was set as the baseline model and its performance analysis was performed at the design point. The engine has the performance of 10,013 lbf thrust and the specific fuel consumption of 0.362 lbm/hr/lbf. The thrust and the specific fuel consumption of the baseline model were compared with those of similar class engines. Based on these results, the turbine design requirements were assigned. In addition, the parametric analysis of the engine, related to aerodynamic and cooling design of the high pressure turbine, was performed. Based on the baseline model engine, the influence of turbine inlet temperature, cooling flow ratio, and high pressure turbine efficiency variations on the engine performance was analyzed.
Performance Characteristic of a Pipe Type Centrifugal Pump
Yu, HyeonJu ; Kang, Shin-Hyoung ;
The KSFM Journal of Fluid Machinery, volume 15, issue 5, 2012, Pages 32~36
DOI : 10.5293/kfma.2012.15.5.032
The positive displacement pump and the regenerative pump are widely used in the range of low specific speed,
[rpm, m3/min, m]. The positive displacement pump is not suitable for miniaturization and operation in high rotational speed. The regenerative pump has a problem with large leakage flow and low efficiency. While the centrifugal pump has advantages of high efficiency, miniaturization and high rotational speed, efficiency drops sharply with decrease in specific speed. Therefore the purpose of this study is to design a new type of centrifugal pump that has advantages of centrifugal pumps in operation in low specific speed. The name of this new type of pump was called 'Pipe type centrifugal pump', since the flow path through the impeller is simple circular pipe. Due to the simple shape of impeller, the manufacturing process is simple and cost is low. There is strong jet flow at the outlet of the impeller. This jet induces flow path loss, meridional dynamic pressure loss and mixing loss. Large disk friction makes the efficiency be limitted in the range of low specific speed. Even though the loss and the low efficiency, 'Pipe type centrifugal pump' represents stable performance, affordable pressure ratio and efficiency better than that of other low specific speed pumps.
Development of a High-efficiency and Low-noise Axial Flow Fan through Combining FanDAS and CFX codes
Lee, Chan ; Kil, Hyun Gwon ; Noh, Myung-Keun ;
The KSFM Journal of Fluid Machinery, volume 15, issue 5, 2012, Pages 37~41
DOI : 10.5293/kfma.2012.15.5.037
High-efficiency and low-noise axial flow fan is developed by combining the FanDAS, a computerized axial fan design/performance analysis system, and CFD software(CFX). Based on fan design requirements, FanDAS conducts 3-D blade geometry design, quasi-3D flow/ performance analyses and noise evaluation by using through-flow analysis method and noise models for discrete frequency and broadband noise sources. Through the parametric studies of fan design variables using FandDAS, preliminary and baseline design is achieved for high efficiency and low noise fan, and then can be coupled with a CFD technique such as the CFX code for constructing final and optimized fan design. The FanDAS-CFX coupled system and its design procedure are applied to actual fan development practice. The FanDAS provides an optimized 3-D fan blade geometry, and its predictions on the performance and the noise level of designed fan are well agreed with actual test results.
A Study on the Development for the Airfoil of Wind Turbine Blade using Digital Wind Tunnel
Kang, Deok Hun ; Woo, Young-Jin ; Lee, Jang Ho ;
The KSFM Journal of Fluid Machinery, volume 15, issue 5, 2012, Pages 42~47
DOI : 10.5293/kfma.2012.15.5.042
Newly updated wing shape to apply small vertical wind turbine is tested with digital wind tunnel in this study. Digital wind tunnel is designed to reduce length of wind tunnel and also to maximize its area of test section. Same DC fans of ninety six are installed in the end side of its rectangular duct and air can be blown out to the other side to have uniform flow with same electricity power. New wing is concluded using experimental plan and analysis with 4-parameters and 3-levels, and tested with digital wind tunnel. It shows better performance in lift to drag ratio, and can applied to the wind turbine for the higher torque and lower thrust.
Three-Dimensional Noise Analysis of an Axial-Flow Fan using Computational Aero-Acoustics
Kim, Joo-Hyung ; Kim, Jin-Hyuk ; Shin, Seungyeol ; Kim, Kwang-Yong ; Lee, Seungbae ;
The KSFM Journal of Fluid Machinery, volume 15, issue 5, 2012, Pages 48~53
DOI : 10.5293/kfma.2012.15.5.048
This paper presents a systematic procedure for three-dimensional noise analysis of an axial-flow fan by using computational aero-acoustics based on Ffowcs Williams-Hawkings equation. Flow-fields of a basic fan model are simulated by solving three-dimensional, unsteady, Reynolds-averaged Navier-Stokes equations using the commercial code ANSYS CFX 11.0. Starting with steady flow results, unsteady flow analysis is performed to extract the fluctuating pressures in the time domain at specified local points on the blade surface of the axial flow fan. The perturbed density wave by rotating blades reaches at the observer position, which is simulated by an in-house noise prediction software based on Ffowcs Williams-Hawkings equation. The detailed far-field noise signatures from the axial-flow fan are analyzed in terms of source types, field characteristics, and interpolation schemes.
A Study on the Flow Characteristics of Aircraft Wing Surface with Various Dimple Patterns
Hong, Woo ; Lee, Jong-Chul ; Kim, Youn-Jea ;
The KSFM Journal of Fluid Machinery, volume 15, issue 5, 2012, Pages 54~59
DOI : 10.5293/kfma.2012.15.5.054
In order to have the high efficiency of aircraft wing and to improve the energy efficiency in field of eco-friendly transportation, the performance characteristics of the aircraft wing were studied with the change of lift to drag ratio through the CFD analysis. The design process was focused on generating the high lift force and low drag force as the lift to drag ratio was increased. In this paper, various dimple patterns were numerically designed to investigate the flow characteristics. Hexagon-and circle-shaped dimples, dimple distance and position were changed as the artificial conditions. The numerical analyses were conducted by using the commercial code, ANSYS CFX. Numerical results dependent on the turbulence intensity and lift to drag ratio distribution were graphically depicted for various dimple patterns.
Study on Surface Vortices in Pump Sump
Long, Ngo Ich ; Shin, Byeong Rog ; Doh, Deog-Hee ;
The KSFM Journal of Fluid Machinery, volume 15, issue 5, 2012, Pages 60~66
DOI : 10.5293/kfma.2012.15.5.060
One of commonly physical phenomena encountered in pump sump systems in which its significant influence to the hydraulic performance of pump system plays an important role in the field of fluid engineering, is the appearance of free surface and submerged vortices. In this paper, a study of the vortices behavior and their formative mechanism of asymmetry is considered in this paper by using numerical approach. The Reynolds-Averaged Navier-Stokes (RANS) equations and k-omega Shear Stress Transport turbulence model used to describe the properties of turbulent flows, in company with VOF multiphase model, are implemented by Fluent code with multi-block structured grid system. In the numerical simulation, the calculated elevation of air-water interface and vortex core contours are used to classify visually surface vortices as well as submerged vortices. It is shown that the free surface vortex is identified by the concavity of liquid region from the free surface and swirling flow at that own plane. To investigate the distinctive behavior of these vortices corresponding to each given flow rate at the same water level, some numerical testing of them are considered here in such a manner that the flow pattern of surface vortex are obtained similarly to the obtained results from experiment. Furthermore, the influence due to the change of grid refinement and the variation of depth of the concavity are also considered in this paper. From that, these influential factors will be implemented to design a good pump sump with higher performance in the future.