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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 17, Issue 6 - Dec 2014
Volume 17, Issue 5 - Oct 2014
Volume 17, Issue 4 - Aug 2014
Volume 17, Issue 3 - Jun 2014
Volume 17, Issue 2 - Apr 2014
Volume 17, Issue 1 - Feb 2014
Selecting the target year
Effect of Anti-Vortex Hole Angle on the Flat Plate Film Cooling Effectiveness
Park, Soon Sang ; Park, Jung Shin ; Lee, Sang Hoon ; Moon, Young Gi ; Kwak, Jae Su ;
The KSFM Journal of Fluid Machinery, volume 17, issue 5, 2014, Pages 5~10
DOI : 10.5293/kfma.2014.17.5.005
In this paper, the experimental study was carried to investigate the effect of angle of the anti-vortex holes on the film cooling effectiveness on a flat plate. The pressure sensitive paint technique was applied to measure the film cooling effectiveness. Two anti-vortex hole angles of
with respect to the primary hole were considered, and the simple cylindrical hole case was also tested. The blowing ratio based on the cylindrical hole was 0.5 and the same flow rate was kept for all anti-vortex hole cases. Results showed that the film cooling effectiveness for the anti-vortex hole cases were much higher than that of the cylindrical case. Among the anti-vortex hole cases,
angle anti-vortex hole case showed higher film cooling effectiveness than that by the
angle anti-vortex hole case.
Study on Optimal Design and Performance Test of Chilled Beam Unit
Kim, Jung-Yup ; Shin, Hyun-Jun ; Joo, Sang-Hyun ; Kim, Ji-Seok ;
The KSFM Journal of Fluid Machinery, volume 17, issue 5, 2014, Pages 11~18
DOI : 10.5293/kfma.2014.17.5.011
Chilled Beam system is the kind of water-air system which reduces the conveyance energy for air conditioning as well as allows efficient installation and comfortable indoor environment, and has been increasingly popular mainly in Europe. To effectively install such Chilled Beam system domestically, it is necessary to develop the product considering domestic climatic condition and the requirements for air conditioning system, and particularly the way to deal with condensation during operation of cooling system in summer shall be provided. In this study, the optimal design on induction structure of Chilled Beam unit was carried out through a numerical method, and the performance test for the prototype of unit was conducted in a real-scale experiment facilities of Chilled Beam unit. While the flowrate of 1st air is 101.3 CMH, the pressure in pressure chamber is 158.7 Pa and the cooling capacities of 1st air side and 2nd air side are 498.1 W and 709.5 W respectively.
Effect of Guide Nozzle Shape on the Performance Improvement of a Very Low Head Cross Flow Turbine
Chen, Zhenmu ; Singh, Patrick Mark ; Choi, Young-Do ;
The KSFM Journal of Fluid Machinery, volume 17, issue 5, 2014, Pages 19~26
DOI : 10.5293/kfma.2014.17.5.019
The cross flow turbine attracts more and more attention for its relatively wide operating range and simple structure. In this study, a novel type of micro cross flow turbine is developed for application to a step in an irrigational channel. The head of the turbine is only H=4.3m and the turbine inlet channel is open ducted type, which has barely been studied. The efficiency of the turbine with inlet open duct channel is relatively low. Therefore, a guide nozzle on the turbine inlet is attached to improve the performance of the turbine. The guide nozzle shapes are investigated to find the best shape for the turbine. The guide nozzle plays an important role on directing flow at the runner entry, and it also decreases the negative torque loss by reducing the pressure difference in Region 1. There is 12.5% of efficiency improvement by attaching a well shaped guide nozzle on the turbine inlet.
Effects of Rotational Speed on the Performance in a Transonic Axial Compressor with a Dihedral Stator
Hwang, Dongha ; Choi, Minsuk ; Baek, Jehyun ;
The KSFM Journal of Fluid Machinery, volume 17, issue 5, 2014, Pages 27~36
DOI : 10.5293/kfma.2014.17.5.027
This paper presents a numerical investigation of the effect of the rotation speed on the performance in a transonic axial compressor with the dihedral stator. Four stator geometries with different stacking line variables were tested in the flow simulations over the whole operating range. It was found that a large shroud loss at the rotor outlet and the subsequent shroud corner separation in the stator passage occurred at low mass flow rate with the 100 % design speed. The hub dihedral stator could suppress the shroud loss region and consequently improve the stall margin. In case of the 70 % design speed condition as the mass flow rate decreased, it was seen that the high loss region was placed at the midspan of the rotor passage. The dihedral stator slightly affected the local diffusion factor, but the performance of the compressor was not changed.
Positive Research About Water Aeration Improvement to Break Thermal Stratification of Dam
Park, Jong-Ho ; Ra, Beyong-Pil ;
The KSFM Journal of Fluid Machinery, volume 17, issue 5, 2014, Pages 37~42
DOI : 10.5293/kfma.2014.17.5.037
In Korea while the dam or reservoir is an important water resource, the value of this water resource is deteriorating by thermal-induced stratification. To ameliorate the water quality of reservoir by breaking stratification the use of air diffuser system is now widespread in Korea. According to the previous research, dynamics of bubble plume and destratification efficiency depended upon two dimensionless groupings; Mh and Pn suggested by Asaeda et al (1993). However, these two variables only include Q, N, H, g, u. and installed Boryeong reservior in appropriate width of water aeration, air dose and number of installations after calculating by applying these figures. This paper is performed to find out effect analysis about water aeration improvement to break thermal stratification.
The Study on the Bi-directional Ejection Air Curtain System for Blocking Smoke Diffusion in case of Tunnel Fire
Yang, Sang-Ho ; Choi, Young-Seok ; Kim, Jung-Yup ; Kim, Nam-Goo ; Kim, Kyung-Yup ;
The KSFM Journal of Fluid Machinery, volume 17, issue 5, 2014, Pages 43~53
DOI : 10.5293/kfma.2014.17.5.043
This paper presents a the study on air curtain system of top and bottom bi-directional jet air discharge for blocking the spread of smoke in case of tunnel fire. The five kinds different air curtains of A, B, C, D, and E of models for various performance tested after manufactured. A results of the various performance test obtained the best efficiency from E model air curtain. And optimize the injection angle of the air curtain nozzle through the three-dimensional computational fluid dynamics (CFD) analysis and analyzed the effects of external pressure of tunnel. and also single factor design have been applied. At present, our attention is focused on the velocity distribution(flow width and flow position) of 1.5m on the ground in tunnel. Also, analyzed the influence of draft in the tunnel. Detailed effects of discharge angle of air curtain and velocity at nozzle exit are discussed.
A Numerical Study on Aerodynamic Characteristics in Tunnel for High Speed Combi Train-HSB
Rho, Joo-Hyun ;
The KSFM Journal of Fluid Machinery, volume 17, issue 5, 2014, Pages 54~59
DOI : 10.5293/kfma.2014.17.5.054
The new high speed combi train prototype project was developed which named HSB. It runs over the speed of 330km/h. As the speed of the train exceeds over 300km/h, due to pressure change in tunnel, aerodynamic problems such as sudden drag increase, severe acoustic noise, passenger discomfort and tunnel pressure sonic boom were occurred. This aerodynamic characteristics in tunnel should be reviewed in early design state to enhance the performance and driving quality of new high speed train. In this paper, the aerodynamic characteristics in tunnel for HSB such as pressure waves in tunnel, a rate of pressure change in cabin and micro pressure wave that cause sonic boom outside tunnel are analyzed by 2D axisymmetric CFD simulations. The results are also compared with the value for ordinary high speed train like the KTX-Sancheon. It is helpful how to design the configuration of HSB train. Finally it shows that the HSB train was well designed in tunnel condition because all values fulfill the criterions on UIC code and Korean national regulations.
Performance and Cavitation Analysis on Tidal Current Turbine for Low Water Level Channel
Chen, Chengcheng ; Choi, Young-Do ;
The KSFM Journal of Fluid Machinery, volume 17, issue 5, 2014, Pages 60~66
DOI : 10.5293/kfma.2014.17.5.060
Most tidal current turbine designs are focused on medium and large scale for deep sea, less attention is paid in low water level channel, such as the region around the islands and costal sea. This study is to develop a horizontal axis tidal current turbine rotor blade which is applicable to low water level island region in southwest coastal region of Korea. In this study, the hydrofoil NACA63-415 and NACA63-817 are both adopted to analyze. The blade using NACA63-817 showed the higher maximum power coefficient and good performance at small TSR (Tip Speed Ratio), which gives the blade more advantages in operating at lower water level channel, where is characterized by the fast-flowing water. The cavitation pattern of hydrofoil is predicted by the CFD analysis and verified that the NACA63-817 is the appropriate hydrofoil in the test site of tidal current resource and the hydrofoil showed considerable performance in avoiding cavitation.
Internal Flow Analysis on an Open Ducted Cross Flow Turbine with Very Low Head
Wei, Qingsheng ; Hwang, Yeong-Cheol ; Choi, Young-Do ;
The KSFM Journal of Fluid Machinery, volume 17, issue 5, 2014, Pages 67~71
DOI : 10.5293/kfma.2014.17.5.067
Recently, the cross flow turbine attracts more and more attention for its good performance over a large operating regime at off design point. This study adopts a very low head cross flow turbine that has barely been studied before, and investigates the effect of air layer on the performance of the cross flow turbine. As open duct is applied in this study and free surface model is used between the air layer and water, an engineering definition of efficiency, instead of traditional definition of efficiency, is used. As torque at the runner fluctuates up and down at a reasonable limit, statistical method is used. Pressure and water volume fraction contours are shown to present the characteristics of air-water flow. With constant air suction in the runner chamber, the water level gradually drops below the runner and efficiency of the turbine can be raised by 10 percent. All considered, the effect of air layer on the performance of turbine is considerable.
Internal Flow Characteristics of a Steelworks Sintering Cooler by the Duct Shape of Cooler Fan Outlet
Choi, Young-Do ; Kim, Kyoung-Hoon ;
The KSFM Journal of Fluid Machinery, volume 17, issue 5, 2014, Pages 72~77
DOI : 10.5293/kfma.2014.17.5.072
Because of overload working condition of sintering cooler, the cooler fan often suffers the break or damage of rotor blade and fixing shaft. Therefore, internal flow characteristics of a steelworks sintering cooler fan by the duct shape of the cooler fan outlet, such as duct outlet opening ratio, duct height and dividing wall shape on the duct outlet flow pattern are examined in detail. The results show that relatively short duct wall height and attachment of dividing wall shape improves flow patterns considerably.
Design Strategies for Multi-Stage Axial Turbines
Kang, Young-Seok ; Rhee, DongHo ; Cha, BongJun ; Yang, SooSeok ;
The KSFM Journal of Fluid Machinery, volume 17, issue 5, 2014, Pages 78~82
DOI : 10.5293/kfma.2014.17.5.078
This paper describes a brief aerodynamic design procedure of multi-stage axial turbine. The design procedure was established including one dimensional scratch design, through flow analysis with empirical correlations, two dimensional airfoil design and three dimensional airfoil stacking. Detailed aerodynamic performance assessment was done with full three dimensional CFD method at the design and off design conditions to construct turbine performance map. With the present method, aerodynamic design procedure of 1st and 2nd stages of high pressure turbine for 10,000lbf class turbofan engine was introduced.
A Study on the Performance Evaluation of Variable-speed Drive Pump
Suh, Sang-Ho ; Kim, Hyoung-Ho ; Rakibuzzaman, Rakibuzzaman ; Kim, Kyung-Wuk ; Yoon, In-Sik ;
The KSFM Journal of Fluid Machinery, volume 17, issue 5, 2014, Pages 83~88
DOI : 10.5293/kfma.2014.17.5.083
Pumps are widely used in industrial plants, energy systems, ships etc. Generally they consume nearly 20% each nation's total electrical energy. The objective of this study is to find performance evaluating method for variable-speed drive pump. In order to evaluate the variable-speed pump performance energy saving rate for the variable-speed pump is applied and compared with that of constant-speed pump.