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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 14, Issue 6 - Dec 2011
Volume 14, Issue 5 - Oct 2011
Volume 14, Issue 4 - Aug 2011
Volume 14, Issue 3 - Jun 2011
Volume 14, Issue 2 - Apr 2011
Volume 14, Issue 1 - Feb 2011
Selecting the target year
Effect of Cone Angle of a Seven-Hole Probe on the Accuracy Flow Measurement
Lee, Yong-Jin ; Park, Jung-Shin ; Nho, Young-Cheol ; Jeon, Chang-Soo ; Kwak, Jae-Su ;
The KSFM Journal of Fluid Machinery, volume 14, issue 5, 2011, Pages 5~11
DOI : 10.5293/kfma..2011.14.5.005
In this study, the effect of cone angle of seven-hole probe on the accuracy of measured flow angle and velocity has been investigated. The seven-hole probe consisted of seven 1mm OD stainless inner tubes and one 3mm ID stainless tube. Six cone angles of
were tested. Calibrations of the seven-hole probes were conducted within
range with the interval of
. Analysis results show that the effect on the cone angle was not significant on the accuracy of the measured flow angle, pressure, and velocity. However, the data reduction method had more effect on the measurement accuracy.
A Numerical Study on the Performance Analysis of the Mixed Flow Pump for FPSO
Kang, Kyung-Won ; Kim, Young-Hun ; Kim, Young-Ju ; Woo, Nam-Sub ; Kwon, Jae-Ki ; Yoon, Myung-O ;
The KSFM Journal of Fluid Machinery, volume 14, issue 5, 2011, Pages 12~17
DOI : 10.5293/kfma..2011.14.5.012
The seawater lift pump system is responsible for maintaining the open canal level to provide the suction flow of circulating water pump at the set point. The objective of this paper is to design a 2-stage mixed flow pump (for seawater lifting) by inverse design method and to evaluate the overall performance and the local flow fields of the pump by using a commercial CFD code. Rotating speed of the impeller is 1,750 rpm with the flow rate of 2,700
/h. Finite volume method with structured mesh and realized k-
turbulent model is used to guaranty more accurate prediction of turbulent flow in the pump impeller. The numerical results such as static head, brake horse power and efficiency of the mixed flow pump are compared with the design data. The simulated results are good agreement with the design data less 3% error.
Analysis on the Flow and the Byproduct Particle Trajectory of Roots Type Vacuum Pump
Lee, Chan ; Kil, Hyun-Gwon ; Noh, Myung-Keun ;
The KSFM Journal of Fluid Machinery, volume 14, issue 5, 2011, Pages 18~23
DOI : 10.5293/kfma..2011.14.5.018
A CFD analysis method is developed and applied for investigating the gas flow and the byproduct particle trajectory in Roots type vacuum pump. The internal fluid flow and thermal fields between the rotors and the housing of vacuum pump are analyzed by using the dynamic mesh, the numerical methods for unsteady 2-D Navier-Stokes equation and the standard k-
turbulence model of the Fluent code. Coupled with the flow simulation results, the particle trajectory of the byproduct flowing into the pump with gas stream is analyzed by using discrete phase modeling technique. The CFD analysis results show the pressure, the velocity and the temperature distributions in pump change abruptly due to the rotation of rotors, and back flows are produced due to the strong reverse pressure gradients at rotor/rotor and rotor/housing clearances. The predicted byproduct particle trajectory results also show the particles impinge on the clearance surfaces between the housing and the rotor of pump and then may form the deposit layer causing the failure of pump.
Prediction of Power and Efficiency Requirement of Motor/generator for 500W Class Micro Gas Turbine Generator Considering Losses
Park, Cheol-Hoon ; Choi, Sang-Kyu ; Ham, Sang-Yong ;
The KSFM Journal of Fluid Machinery, volume 14, issue 5, 2011, Pages 24~30
DOI : 10.5293/kfma..2011.14.5.024
500W class MTG(Micro turbine generator) operating at 400,000 rpm is under development. From the cycle analysis, it is decided that the self-sustaining speed of MTG is 200,000rpm and the generating speed is 400,000 rpm. Therefore, motor should be designed so that it is able to rotate the rotor up to 200,000rpm and generator should designed so that it is able to generate 500W output at 400,000rpm. First step to design motor/generator is to determine the power and efficiency requirement. Not only the power into the compressor and from the turbine at the operating speed but also the mechanical and electrical losses should be considered in determining the power and efficiency requirement. This study presents the procedure and the results of determining the power and efficiency requirement considering the mechanical and electrical losses depending on the rotating speed which is measured from the experiment.
Numerical Optimization of a Transonic Axial Compressor with Casing Grooves for Improvement of Operating Stability
Kim, Jin-Hyuk ; Choi, Kwang-Jin ; Kim, Kwang-Yong ;
The KSFM Journal of Fluid Machinery, volume 14, issue 5, 2011, Pages 31~38
DOI : 10.5293/kfma..2011.14.5.031
Optimization using a hybrid multi-objective evolutionary algorithm coupled with response surface approximation has been performed to improve the performance of a transonic axial compressor with circumferential casing grooves. In order to optimize the operating stability and peak adiabatic efficiency of the compressor with circumferential casing grooves, tip clearance, angle distribution at blade tip and the depth of the circumferential casing grooves are selected as design variables. Three-dimensional Reynolds-averaged Navier-Stokes equations with the shear stress transport turbulence model are discretized by finite volume approximations. The trade-off between two objectives with the interaction of blade and casing treatment is determined and discussed with respect to the representative clusters in the Pareto-optimal solutions compared to the axial compressor without the casing treatment.
Study of Flow Control Range according to Valve Type
Park, Jong-Ho ; Park, Han-Yung ;
The KSFM Journal of Fluid Machinery, volume 14, issue 5, 2011, Pages 39~47
DOI : 10.5293/kfma..2011.14.5.039
Flow control range of valve, which is installed on pipeline, varies according to valve type, pipe diameter, pipe length, roughness, and elevation difference of both ends of pipeline. A lot of computation efforts and knowledge are needed to estimate flow control range of valve, considering above many parameters. The table of flow control range of each valve type is presented for convenience of pipeline design engineers who must make decision of valve size and type in this study. Also the reason that butterfly valve is recommended for flow control, and gate valve is forbidden is presented via quantification and figures in this study.
Changes of Mooring Force due to Structural Modification of a Barge Ship
Park, Jung-Hong ; Kim, Kwang-Hoon ; Moon, Byung-Young ; Jang, Tak-Soo ;
The KSFM Journal of Fluid Machinery, volume 14, issue 5, 2011, Pages 48~54
DOI : 10.5293/kfma..2011.14.5.048
Structural modifications of a ship may cause a fatal accident such as sinking and wrecking of ship. Especially, barge ship can be easily reconstructed to load more bulk cargo. In this study, for a real accident case, change of mooring force due to structural modification was analyzed to evaluate accident risk. A two dimensional dynamic model for the barge ship was constructed to compute mooring forces with related to floating motion. The equation of motion was established in Matlab code and buoyancy was calculated by using direct integration of submerged volume. The results showed that wind force, current force, and mooring force after rebuilding was approximately 4.3 kN, 14 kN, 1,561 kN respectively. The maximum force of mooring force according to the length of mooring cable were 1,614 kN at 30 m of mooring cable. Thus, an arbitrary modification of ship lead instability and unreliable result so that illegal rebuilding of ship should be avoided.
Design Optimization of a Printed Circuit Heat Exchanger Using Surrogate Models
Lee, Sang-Moon ; Kim, Kwang-Yong ;
The KSFM Journal of Fluid Machinery, volume 14, issue 5, 2011, Pages 55~62
DOI : 10.5293/kfma..2011.14.5.055
Shape optimization of a Printed circuit heat exchanger (PCHE) has been performed by using three-dimensional Reynolds-Averaged Navier-Stokes (3-D RANS) analysis and surrogate modeling techniques. The objective function is defined as a linear combination of effectiveness of the PCHE term and pressure drop in the cold channels of the PCHE. The cold channel angle and the ellipse aspect ratio of the cold channel are used as design variables for the optimization. Design points are selected through Latin-hypercube sampling. The optimal point is determined through surrogate-based optimization method which uses 3-D RANS analyses at design points. The results of three types of surrogate model are compared each other. The results of the optimizations indicate improved performance in friction loss but low performance in effectiveness than the reference shape.
Numerical Optimization for Performance Improvement of a Tunnel Ventilation Jet fan
Kim, Joon-Hyung ; Kim, Jin-Hyuk ; Kim, Kwang-Yong ; Yoon, Joon-Yong ; Choi, Young-Seok ; Yang, Sang-Ho ;
The KSFM Journal of Fluid Machinery, volume 14, issue 5, 2011, Pages 63~68
DOI : 10.5293/kfma..2011.14.5.063
This paper presents an optimization procedure for performance improvement of a tunnel ventilation jet fan. Optimization techniques based on response surface approximation (RSA) are employed to improve the aerodynamic performance of a tunnel ventilation jet fan. For numerical analysis, three-dimensional Renolds- averaged Navier-Stokes (RANS) equations with shear stress transport turbulence model are discretized by using finite volume approximations and solved on hexahedral grids to evaluate the total efficiency at the operating condition as the objective function. Four geometric variables defining the meridional length and the thickness profile at the hub and shroud in the jet fan rotor are selected as design variables for the numerical optimization. The results of the numerical optimization show that the total efficiency of the optimized model is significantly improved in comparison with the base model.
Rotordynamic Transient Analysis of Vertical Sea Water Lift Pump for FPSO Deep Well
Kim, Byung-Ok ; Yang, Sung-Jin ; Lee, Myung-Ho ;
The KSFM Journal of Fluid Machinery, volume 14, issue 5, 2011, Pages 69~74
DOI : 10.5293/kfma..2011.14.5.069
This paper deals with the detail rotordynamic analysis for the vertical rotor system as development of vertical sea water lift pump for FPSO deep well. In a vertical rotor system, since linearized stiffness and damping coefficients of fluid film bearing are no longer be valid, hence the transient response analysis considering a fluid film force for every journal position in the bearing needs to be required. In this study, the transient response analysis of the proposed vertical pump rotor system was carried out in dry-run and wet-run conditions, respectively. The results show that orbital vibration responses of the rotor system remain stable at rated speed and thereby operating reliability of the vertical rotor system is confirmed. To overcome complexity of calculation pr ocedure and time consuming calculation of transient analysis, the calculating technique of steady-state response analysis is also proposed. The results of steady-state response obtained by applying the proposed technique to the rotor system are good agreement with the reference results, that is, transient responses.