• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 1998년도 유체기계 연구개발 발표회 논문집
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• pp.97-104
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• 1998

The objective of this study is to understand the generation mechanism of sound and to develop a prediction method for the unsteady flow field and the acoustic pressure field of a centrifugal fan. Lowson's method is used to predict the acoustic pressure in a free field. A DVM(discrete vortex method) is used to model the centrifugal fan and to calculate the flow field. In order to compare the experimental data, a centrifugal fan and wedge introduced by Weidemann are used in the numerical calculation and the results are compared with the experimental data.

• Journal of Advanced Marine Engineering and Technology
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• 제18권3호
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• pp.43-51
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• 1994

The design technique of turbo pumps has been developed due to an increasing demand from related industrial fields. But infant stage of turbomachinery in the domestic industry needs more fundamental design method. Among various types of pumps, centrifugal pump was chosen because of its wide industrial application. It is difficult to decide the correct specification of centrifugal impeller, because of its complex flow analysis at the inlet, passage and outlet. This study is limited on the impeller blade design and its related performance analysis.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2001년도 Proceedings of 2001 Korea-Japan Joint Seminar on Particle Image Velocimetry
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• pp.1-5
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• 2001

A particle image velocimetry (PIV) was applied to a flow measurement in a transonic centrifugal impeller. A phase locked measurement technique every $20\%$ blade pitch enabled a reconstruction of a velocity field over one blade pitch. The measured velocity field at the inducer of impeller clearly showed a shock wave generated on the suction surface of a blade.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.148-152
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• 2000

The experimental study was performed to investigate the effects of centrifugal condition on the segregated layers of materials and the compressive strength of concrete for pretensioned spun high strength concrete (PHC) pile. The considering factors in the test were the centrifugal time and the magnitude of centrifugal force. These factors have been found to have found to have the great influence on the segregation and the concrete strength. The moderate centrifugal condition has to be fitted for the quality assurance in the production of PHC pile, especially to provide the adequate concrete cover over the tendons.

• International Journal of Fluid Machinery and Systems
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• 제6권1호
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• pp.11-17
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• 2013

Mini centrifugal pumps having a diameter smaller than 100mm are employed in many fields. But the design method for the mini centrifugal pump is not established because the internal flow condition for these small-sized fluid machines is not clarified and conventional theory is not suitable for small-sized pumps. Therefore, mini centrifugal pumps with simple structure were investigated by this research. Splitter blades were adopted in this research to improve the performance and the internal flow condition of mini centrifugal pump which had large blade outlet angle. The original impeller without the splitter blades and the impeller with the splitter blades were prepared for an experiment. The performance tests are conducted with these rotors in order to investigate the effect of the splitter blades on performance and internal flow condition of mini centrifugal pump. On the other hand, a three dimensional steady numerical flow analysis is conducted with the commercial code (ANSYS-CFX) to investigate the internal flow condition in detail. It is clarified from experimental results that the performance of the mini centrifugal pump is improved by the effect of the splitter blades. Blade-to-blade low velocity regions are suppressed in the case with the splitter blades and total pressure loss regions are decreased. The effects of the splitter blades on the performance and the internal flow condition are discussed in this paper.

• Journal of the Korean Wood Science and Technology
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• 제31권1호
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• pp.61-70
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• 2003

원심법을 이용하여 침엽수 생재 심재부의 조재와 만재에 대한 수분이동경로의 크기를 평가하였다. 또한, 원심처리 후의 포수율 분포와 수분포텐셜의 관계로부터 액체투과성을 측정하였다. 삼나무의 경우, 조재는 0.70 ㎛, 만재는 0.50 ㎛의 반경에서 뚜렷한 피크가 관찰되었다. 솔송나무는 조재와 만재 모두 0.50 ㎛의 반경에서 피크를 나타냈다. 일본전나무와 일본잎갈나무는 조재 0.70 ㎛, 만재 0.30 ㎛의 반경범위에서 피크 값이 관찰되었다. 반면에, 미송과 시트카스푸르수는 뚜렷한 피크 값을 보이지 않았다. 액체투과성은 미송을 제외한 모든 수종에서 조재가 만재보다 좋게 평가되었다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집E
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• pp.801-806
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• 2001

The objective of present study is to find the interaction between volute and impeller of the centrifugal turbomachinery with rectangular cross-sectional volute. Flow measurement were taken in shrouded impeller with 12 backward type blades by using a five-hole pressure probe. The measurements are carried out in 7 flow rate, respectively. Primary function of a centrifugal turbo machinery volute is to serve the flow from the impeller and diffuser to pipe system. For the off-design conditions, Influence of pressure distortion was shown by these measurements. As a result, It has caused the decrease of total efficiency of centrifugal turbomachinery. We have also taken data to design volute by these measurements.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집E
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• pp.672-677
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• 2001

This study has been conducted to design the high efficiency centrifugal compressor for a HFC-134a. The 2-stage centrifugal compressor consists of inlet guide vanes, two impellers with splitters, a deswirler, a vaneless diffuser and a volute casing. We have designed the high efficiency centrifugal compressor by applying the repeated design procedure including a meanline design, a 3D geometry generation of 1st and 2nd impellers etc. Also, a fluid dynamic calculation of impellers and deswirler have been conducting using a commercial code STAR-CD.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1992년도 가을 학술발표회 논문집
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• pp.228-233
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• 1992

The objective of this report is to investigate the effect of factors on the centrifugal compaction of concrete piles with design of experiments. The analysis of sludge and measurement of compressive strength of specimens compacted by centrifugal of vibration were performed. As a result, there were some effective factors like unit content of cement, high and middle centrifugal force and time. It was considered that the process of centrifugal compaction of concrete piles could be optimized with these results.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 1998년도 유체기계 연구개발 발표회 논문집
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• pp.33-41
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• 1998

In this study, the performance prediction programs for centrifugal pumps are developed. To estimate the losses in the centrifugal pump impellers, two-zone model and TEIS(two elements in series) model are applied to the program. The basic concept of two zone model considers the primary zone that is an isentropic core flow and the secondary zone that is non-isentropic region at the impeller exit. The flows through two different zones 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 a 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 to select the effectiveness of the primitive TEIS model were suggested according to the specific speed of the centrifugal pumps.