• The KSFM Journal of Fluid Machinery
• /
• v.7 no.5 s.26
• /
• pp.82-90
• /
• 2004

• Proceedings of the Korean Nuclear Society Conference
• /
• 2005.05a
• /
• pp.7-8
• /
• 2005

• 유체기계공업학회:학술대회논문집
• /
• 2004.12a
• /
• pp.396-401
• /
• 2004

In this paper, a 1MW HAWT(FIL-1000) rotor blade has been designed by BEMT(Blade Element Momentum Theory) with Prandtl's tip loss. Also, a 3-D flow and performance analysis on the FIL-1000 rotor blade has been carried out by using the 3-D Navier-Stokes commercial solver (CFX-5.7) to provide more efficient design techniques to the large-scale HAWT engineers. The rated power and itsapproaching wind velocity at design point (TSR=7.5) are 1MW and 9.99m/s respectively. The rotor diameter is 54.5m and the rotating speed is 26.28rpm. Airfoils such as FFA W-301, DU91-W-250, DU93-W-210, NACA 63418, NACA 63415 consist of the rotor blade from hub to tip. Recent CFX version, 5.7 was adopted to simulate 3-D flow field and to analyze the performance characteristics of the rotor blade. Entire mesh node number is about 730,000 and it is generated by ICEM-CFD to achieve better mesh quality The predicted maximum power occurringat the design tip speed ratio is 931.45kW. Approaching to the root, the inflow angle becomes large, which causesthe blade to be stalled in the region. Therefore, k-$\omega$ SST turbulence model was used to predict the quantitative flow information more accurately. Application of commercial CFD code to optimum blade design and performance analysis was proved to be more effective environment to HAWT blade designers.

• Proceedings of the Korean Nuclear Society Conference
• /
• 2005.10a
• /
• pp.606-607
• /
• 2005

• Nuclear Engineering and Technology
• /
• v.38 no.1
• /
• pp.45-60
• /
• 2006

Presently, the VHTGR (Very High Temperature Gas-cooled Reactor) is considered the most attractive candidate for a GEN-IV reactor to produce hydrogen, which will be a key resource for future energy production. A new concept for a reactor cavity cooling system (RCCS), a critical safety feature in the VHTGR, is proposed in the present study. The proposed RCCS consists of passive water pool and active air cooling systems. These are employed to overcome the poor cooling capability of the air-cooled RCCS and the complex cavity structures of the water-cooled RCCS. In order to estimate the licensibility of the proposed design, its performance and integrity were tested experimentally with a reduced-scale mock-up facility, as well as with a separate-effect test facility (SET) for the 1/4 water pool of the RCCS-SNU to examine the heat transfer and pressure drop and code capability. This paper presents the test results for SET and validation of MARS-GCR, a system code for the safety analysis of a HTGR. In addition, CFX5.7, a computational fluid dynamics code, was also used for the code-to-code benchmark of MARS-GCR. From the present experimental and numerical studies, the efficacy of MARS-GCR in application to determining the optimal design of complicated systems such as a RCCS and evaluation of their feasibility has been validated.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.36 no.7
• /
• pp.683-687
• /
• 2012

The purpose of this paper is to numerically study the characteristics of the indoor air flow of a square ceiling type diffuser according to the vane angle and flow rate. The CFX of ANSYS 13.0 was used for the CFD tool. The size of the room is $6m(X){\times}6m(Y){\times}2.7m(Z)$. The exhaust diffuser was positioned diagonally to the supply diffuser. This diffuser was designed to have many holes, so the air supply had long throw patterns with low velocity decay. The characteristics of the indoor air flow was studied at volume flow rates of 5.1 CMM and 7.4 CMM, and a vane angle from $30^{\circ}$ to $60^{\circ}$, every $10^{\circ}$.

• Korean Journal of Veterinary Service
• /
• v.19 no.3
• /
• pp.213-219
• /
• 1996

Seventy-nine strains of Enterobacteriaceae isolated from 117 slaughtered pigs (bile, urine, small intestine, cecum and rectum) in 1995 were examined for biotypes and susceptibility to 19 antibiotics with MicroScan WalkAway 40/96. The obtained results were as follows : 1. Among the twenty-two species isolated from the samples, Proteus mirabilis, E. coli and Enterobacter cloacae were commonly encountered. 2. The distribution frequency of isolates from cecum, small intestine, rectum, bile, and urine was 31(38.8%), 25(31.3%), 18(22.8%), 3(3.7% ), and 2(2.5% ), respectively. 3. A majority of isolates were sensitive to 16 antibiotics, singly or in combination. And these isolates were commonly susceptible to various antibiotics such as Cp, Ts, Azt, Caz, To, Gm, Cfz, Crm, Am and Cfx, in order. Whereas the Salmonella spp was susceptible to Cf, Ti and Pi, and Proteus mirabilis to Imp, Tim, Cft and Cz. Meanwhile, no effect was found to Cf, Ak and Cax. 4. Among the antibiotic resistant strains, a total of 17 reistant patterns was noted End of these Ak Tim 45(57.0%), Ak Am Cf Cfx Cfz Tim 8(10.1%) and Ak Ti Tim 6(7.6% ) were frequently encountered.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.10 no.5
• /
• pp.389-395
• /
• 2017

This paper showed the difference in the optimum conditions by using the ANSYS CFX simulation program with the changes of the main-blade angle and sub-blade angle. Main-blade Shape 4,which had angle $45^{\circ}$ while other Shapes with angle $0^{\circ}$, was increased to 157.2[%] to 263.2[%] in the power and was increased to 110[%] to 250[%] in the power coefficient. Moreover, when the Shape 5 Fin length of main-blade doubled, the power was 70.8[%] when compared with Shape 1 and 27.5[%] with shape 4.If the main-blade geometry equals shape 1 in the case structure, The power of Case1 was increased to 13.3[%] when compared with Case2. Also, the power coefficient was increased to 15.4[%]. When sub-blade angle was $45^{\circ}$, main-blade was better than the Fin type than the Bended type. The power of Case4 was increased to 47[%] when compared with Csae1 and increased to 13.6[%] with Case 3. Also, the power coefficient was 46.7[%] when compared with Case 1 and 15.8[%] with Case 3.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.37 no.2
• /
• pp.149-154
• /
• 2013

This study was performed to develop a high efficiency submersible axial pump for concentration wastewater treatment. To do this, we simulated the effect of some parameters such as the axial twist angle of a blade(${\beta}$), the radial twist angle of a blade(${\alpha}$) and the length of a blade (l) on pump efficiency using commercial code, ANSYS CFX and BladeGen. The results showed that the axial twist angle of a blade(${\beta}$) was the most sensible parameter on the pump efficiency. And the pump efficiency had a maximum at ${\beta}=20^{\circ}$, ${\alpha}=110^{\circ}$ and l=240 mm.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.37 no.5
• /
• pp.685-691
• /
• 2013

A load-cell-type anemovane operates based on wind vector properties. The developed load-cell-type anemovane is of a fixed type in which the wing does not rotate, unlike in the case of existing anemovanes. The load-cell-type anemovane is required to accurately derive the correlation between the load ratio and the wind direction in order to develop a qualified product. This is because the load ratio repeats every $90^{\circ}$ owing to the use of four load cells, and its value varies nonlinearly according to the wind direction. In this study, we compared analytical results with experimental results. Fluid analysis was carried out using ANSYS CFX. Furthermore, the prototype was tested using a self-manufactured wind tunnel. The wind direction was selected as the design variable. 13 selected wind direction conditions ranging from $0^{\circ}$ to $90^{\circ}$ with an interval of $7.5^{\circ}$ for analysis were defined. Furthermore, 10 wind direction conditions with an interval of $10^{\circ}$ for the experiment were defined. We derived the relations between the pressure ratio and the wind direction through the experiment and fluid analysis.