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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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The KSFM Journal of Fluid Machinery
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Journal DOI :
Korean Fluid Machinery Association
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Volume & Issues
Volume 2, Issue 4 - Dec 1999
Volume 2, Issue 3 - Sep 1999
Volume 2, Issue 2 - Jun 1999
Volume 2, Issue 1 - Mar 1999
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Performance Evaluation of the Gas Turbine for Integrated Ossification Combined Cycle
Lee, Chan ; Lee, Jin-Wook ; Yun, Yong-Seung ;
The KSFM Journal of Fluid Machinery, volume 2, issue 1, 1999, Pages 7~14
This simulation method is developed by using GateCycle code for the performance evaluation of the gas turbine in IGCC(Integrated Gasification Combined Cycle) power plant that uses clean coal gas fuel derived from coal gasification and gas clean-up processes and it is integrated with ASU(Air Separation Unit). In the present simulation method, thermodynamic calculation procedure is incorporated with compressor performance map and expander choking models for considering the off-design effects due to coal gas firing and ASU integration. With the clean coal gases produced through commercially available chemical processes, their compatibility as IGCC gas turbine fuel is investigated in the aspects the overall performance of the gas turbine system. The predictions by the present method show that the reduction of the air extraction from gas turbine to ASU results in a remarkable increase in the efficiency and net power of gas turbines, but it is accompanied with a shift of compressor operation point toward to surge limit. In addition, the present analysis results reveal the influence of compressor performance characteristics of gas turbine have to be carefully examined in designing the ASU integration process and evaluating the overall performance parameters of the gas turbine in IGCC Power plant.
Performance Variations of a Small Centrifugal Compressor with Exit Blade Thickness
Kang, Shin-Hyoung ; Cho, Woon-Je ; Yun, Ha-Yong ; Lee, Seung-Kap ;
The KSFM Journal of Fluid Machinery, volume 2, issue 1, 1999, Pages 15~21
Some sized centrifugal compressors were designed and their performance measured to investigate the effects of exit blade thickness, width and back swept angle. The impeller of larger blade thickness shows low pressure ratio compared with that of smaller ones. Backswept angle also have a large effect on the efficiency. Measured values of slip factor are quite different from the estimated values of the Wiesner-Busemann model and an increase in the flow late.
Aerodynamic Design of the Axial Fan
Sohn, Sang-Bum ; Joo, Won-Gu ; Cho, Kang-Rae ; Nam, Hyung-Baik ; Yoon, In-Kyu ; Nam, Leem-Woo ;
The KSFM Journal of Fluid Machinery, volume 2, issue 1, 1999, Pages 22~28
In this study, a preliminary design method of the axial fan was systematically established based on the two-dimensional cascade theory. Flow deviation, lift coefficient, distribution of velocity and pressure coefficient on blade surfaces were predicted by an inviscid flow theory of Martensen method, which was also applied to select an airfoil for required performance in the present design process. The aerodynamic performance of designed blades can be predicted quickly and reasonably by using the through-flow calculation method in the preliminary design process. It would be recommendable to adopt three-dimensional viscous flow calculation at the final design refinement stage.
A Study on Numerical Optimization Method for Aerodynamic Design
Jin, Xue-Song ; Choi, Jae-Ho ; Kim, Kwang-Yong ;
The KSFM Journal of Fluid Machinery, volume 2, issue 1, 1999, Pages 29~34
To develop the efficient numerical optimization method for the design of an airfoil, an evaluation of various methods coupled with two-dimensional Naviev-Stokes analysis is presented. Simplex method and Hook-Jeeves method we used as direct search methods, and steepest descent method, conjugate gradient method and DFP method are used as indirect search methods and are tested to determine the search direction. To determine the moving distance, the golden section method and cubic interpolation method are tested. The finite volume method is used to discretize two-dimensional Navier-Stokes equations, and SIMPLEC algorithm is used for a velocity-pressure correction method. For the optimal design of two-dimensional airfoil, maximum thickness, maximum ordinate of camber line and chordwise position of maximum ordinate are chosen as design variables, and the ratio of drag coefficient to lift coefficient is selected as an objective function. From the results, it is found that conjugate gradient method and cubic interpolation method are the most efficient for the determination of search direction and the moving distance, respectively.
Measurement of the Velocity Field of Rotor-Stator in a Centrifugal Turbine Pump Using PIV
Im, Yu-Cheong ; Seo, Min-Sik ; Lee, Young-Ho ;
The KSFM Journal of Fluid Machinery, volume 2, issue 1, 1999, Pages 35~42
The present experimental study is focused on the application of multi-point simultaneous measurement by PIV(Particle Image Velocimetry) to rotor-stater region within centrifugal turbine pump. Six different kinds of rpm(120, 500, 1000, 1500, 2000 and 2500) are selected as experimental condition. Optimized cross correlation identification to obtain velocity vectors is implemented with direct calculation of correlation coefficients. Fine optical setup concerned with PIV performance is arranged for the accurate PIV measurement of high-speed complex flow. The instantaneous and time-mean velocity distribution and velocity profile are represented quantitatively at the rotor and stator region.
Flow Field Analysis of a Centrifugal Fan
Shin, Dong-Shin ; Im, Jong-Soo ; Kim, Chang-Seong ; Rho, O-Hyun ; Lee, Soo-Gab ;
The KSFM Journal of Fluid Machinery, volume 2, issue 1, 1999, Pages 43~49
Flow field and near-field noise of a centrifugal fan has been studied with an efficient compressible method and STAR-CD. The flow field of the centrifugal fan is assumed to be two-dimensional. Most of the compressible studies have been done by inviscid solver because viscous simulation shows little difference. The near field noise is estimated in terms of sound pressure level in frequency domain transformed from the computed pressure fluctuations using FFT. The simulation has been done on various design elements such as impeller blade shapes, the number of blades and cut-off clearance. The comparison shows that the number of blades has a significant effect on near-field noise without losing aerodynamic performance.
Experimental Study of the Effects of Dimensional Parameters on the Performance of Small Centrifugal Fans
Choi, Jong-Soo ; Rhee, Wook ;
The KSFM Journal of Fluid Machinery, volume 2, issue 1, 1999, Pages 50~55
The performance of a centrifugal fan depends on the dimensional parameters of impeller, such as the inlet and exit diameter, area ratio, relative flow angles to the blade, and the number of blades. These design parameters, however, are inter-related, so it is very difficult to identify the effect of each parameter on the fan performance. In this experimental study the effects of the design parameters on the performance of a small centrifugal impeller being used for vacuum cleaners are investigated. A total of 30 shrouded impellers with 120mm diameter were tested and the results were non-dimensionalized to compare their performance.
Performance Prediction of Centrifugal Pumps using a Two Zone Model
Choi, Young-Seok ; Shim, Jae-Hyeok ; Kang, Shin-Hyoung ;
The KSFM Journal of Fluid Machinery, volume 2, issue 1, 1999, Pages 56~63
In this study, the performance prediction programs for centrifugal pumps are developed. To estimate the losses in the centrifugal pump impellers, a two-zone model and TEIS(two elements in series) model are applied to the program. The basic concept of a two zone model considers the primary zone that is an isentropic core flow and the secondary zone that has a non-isentropic region at the impeller exit. The flow goes through two different zones and is mixed out at the impeller exit and the mixing process occurs with an increase in entropy, a decrease in total pressure. The level of the core flow diffusion in an impeller was calculated using TEIS(two elements in series) model. The effects of various parameters which are used in this program on the prediction of head and efficiency are discussed. The correlation curves used to select the effectiveness of the primitive TEIS model were suggested according to the specific speed of the centrifugal pumps.
Performance Analysis of Three-Dimensional Transonic Centrifugal Compressor Diffuser
Kim, Sang-Dug ; Song, Dong-Joo ;
The KSFM Journal of Fluid Machinery, volume 2, issue 1, 1999, Pages 64~72
CSCM upwind flux difference splitting compressible Navier-Stokes method has been used to predict the transonic flows in a centrifugal compressor diffuser. The modified cyclic. TDMA and the mass flux boundary conditions were used as boundary conditions of the diffuser analysis. Broad flow separation on the suction surface near the hub and shroud was observed from the results of the mass flow rates 5.8, 6.0 and 6.2kg/s at 27000 rpm. The three-dimensional flow analysis predicted successfully that the static pressure increased and the total pressure decreased through the flow passage of the channel diffuser when compared to two-dimensional analysis due to the strong effect of the three-dimensional flow. The mass averaged loss coefficients and pressure coefficients were also studied.
Evaluation of Tip Leakage Loss and Reduction of Efficiency of Axial Turbomachinery Using Numerical Calculation
Ro, Soo-Hyuk ; Cho, Kang-Rae ;
The KSFM Journal of Fluid Machinery, volume 2, issue 1, 1999, Pages 73~80
Leakage vortices formed new blade tip causes an increase of total pressure loss near the casing endwall region and as a result, the efficiency of rotor decreases. The reduction of rotor efficiency is related to the size of the tip clearance. In this study, the three-dimensional flowfields in an axial flow rotor were calculated by varying the tip clearance under various flow rates, and the numerical results were compared with experimental ones. The effects of tip clearance and attack angle on the leakage vortex and overall performance, and the loss distributions were investigated through numerical calculations. In this study, tip leakage flow rate and total pressure loss by tip clearance were evaluated using numerical results and approximate equations were presented to evaluate the reduction of rotor efficiency by tip leakage flow.
Measurement Techniques on Unsteady Flow at Impeller Exit
Shin, You-Hwan ; Kim, Kwang-Ho ;
The KSFM Journal of Fluid Machinery, volume 2, issue 1, 1999, Pages 81~87
This study presents the measurement techniques on the periodic fluctuating flow such as the discharge flow of a centrifugal impeller in an unstable operating region. During rotating stall, the flow at the exit of a centrifugal compressor impeller fluctuates periodically with a lower frequency than that of the blade passing. To observe the blade-to-blade flow characteristics during the rotating stall, the phases of all the sampled data sets should be adjusted to those of the reference signals with two processes, in these processes, DPLEAT (Double Phase-Locked Ensemble Averaging Technique) can be used. From these measurements and data processing techniques, the characteristics illustrated a blade-to-blade flow with high frequency, but also a periodic rotating stall flow with a low frequency at the centrifugal impeller exit which was clearly observed.
Modification of a Two Stage Axial Compressor of a Turboshaft Engine for Helicopters
Kim, Jin-Han ; Kim, Chun-Taek ; Lee, Dae-Sung ;
The KSFM Journal of Fluid Machinery, volume 2, issue 1, 1999, Pages 88~95
This paper introduces the part of efforts to develop a derivative type turboshaft engine from an existing baseline engine for multi-purpose helicopters aiming at 4000 kg of take-off weight for 10-12 passengers. As a first step in meeting the development goal of increasing the output power from 720 hp to 840hp with minimum modification, a two stage axial compressor was redesigned to obtain the higher pressure ratio by removing the inlet guide vane and increasing the chord length. As a result, a two stage axial compressor was designed to facilitate a flow rate of 3.04 kg/s, a pressure ratio of 2.01 and an adiabatic efficiency of
. Its performance tests were carried out and verification of test results and redesign are under progress. Aerodynamic and structural analyses of the preliminary design are mainly described in this paper.
A Numerical Study on Flow through a Cross Flow Fan: Effect of Blade Shapes on Fan Performance
Hur, Nahm-Keon ; Kim, Wook ; Kang, Shin-Hyoung ;
The KSFM Journal of Fluid Machinery, volume 2, issue 1, 1999, Pages 96~102
Cross flow fans are used in various applications, especially in industrial ventilation applications and in room air conditioners, due to their superior performance characteristics. Unlike radial and/or axial fans, the design of cross flow fans have been mostly based on earlier experiences and experiments. In the present study, numerical computations of flow fields through a cross flow fan used in room air conditioner are performed to investigate the detailed flow fields and to study the effect of the blade shape on performance curves to aid better design of the fan. Despite some discrepancies between the two results, it is seen from the present study that the computational results agree quite well with the qualitative experimental results. It is also shown from the present study that by having a different shape of blade, it is possible to achieve about
increase in flow rates. The stimulating results of the present study can be used in the design of high performance cross flow fans with the use of optimal design algorithm and experimental verifications.
Transient Flow Instability inside a Gas Turbine Shaft
Hur, Nahm-Keon ; Won, Chan-Shik ;
The KSFM Journal of Fluid Machinery, volume 2, issue 1, 1999, Pages 103~107
Transient flow inside a hollow shaft of a Gas Turbine engine during sudden engine stop may result in non uniform heat transfer coefficients in the shaft due to flow instability similar to steady Taylor vortex, which may decrease the lifetime of the shaft. In the present study, transient Taylor vortex phenomena inside a suddenly stopped hollow shaft are studied analytically. Flow visualization is also performed to study the shape and onset time of Taylor Vortices for various initial rotational speed.
A Study on Unsteady Flow and Movement around a Check Valve in a Scroll Compressor
Lee, Jin-Kab ; Rew, Ho-Seon ;
The KSFM Journal of Fluid Machinery, volume 2, issue 1, 1999, Pages 108~113
In a scroll compressor it is generally accepted that a check valve is necessary to prevent reverse rotation of the scrolls. The check valve is subjected to discharge pulsations and their resultant forces. The flow phenomena around the check valve may affect the efficiency and the noise level significantly. The motivation of this study is to understand the flow phenomena and the unstable motion of the check valve on operating conditions in order to identify reasons raising noise and improve the performance of the check valve. In this study, unsteady flow simulation was performed using CFD and the pressure distribution around the check valve was obtained. This paper also shows that unstable motion of the check valve on standard operating conditions through theoretical analysis and flow visualization.
Three-Dimensional Flow in Turbomachinery
Joo, Won-Gu ;
The KSFM Journal of Fluid Machinery, volume 2, issue 1, 1999, Pages 114~126
펌프 산업계의 동향
The KSFM Journal of Fluid Machinery, volume 2, issue 1, 1999, Pages 127~127
펌프시장 현황 및 국내 펌프업체의 발전전략
The KSFM Journal of Fluid Machinery, volume 2, issue 1, 1999, Pages 128~138
펌프 및 송풍기 관련 규경의 선진화연구
The KSFM Journal of Fluid Machinery, volume 2, issue 1, 1999, Pages 139~142
설문조사를 통한 펌프산업의 현황파악
The KSFM Journal of Fluid Machinery, volume 2, issue 1, 1999, Pages 143~149
Sealmatic Pump의 기술현황
The KSFM Journal of Fluid Machinery, volume 2, issue 1, 1999, Pages 150~154
Dynamic Seal 펌프의 개발
The KSFM Journal of Fluid Machinery, volume 2, issue 1, 1999, Pages 155~155