• Title, Summary, Keyword: Butterfly

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Cavitation and Loss Reductions of Butterfly Valve by Modifying the Shaft Boss Profile (축 보스 형상 변형을 이용한 버터플라이 밸브의 캐비테이션과 유동손실 감소)

  • Kim, J.R.;Moon, Y.J.;Han, Y.S.
    • 한국전산유체공학회:학술대회논문집
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    • pp.605-608
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    • 2008
  • In this paper, a numerical investigation of three-dimensional, two-phase flow field around a butterfly valve is conducted. The butterfly valves that have different opening angles, $10^{\circ}{\sim}90^{\circ}$, and two profiles of the shaft boss are compared with various cavitation numbers and Reynolds numbers. This paper focused on the flow analysis in the original butterfly valve and new design butterfly valve in order to decrease cavitation and loss. It is found that the butterfly valve with a cone-type shaft boss greatly reduces the cavitation and loss, compared to the original shaft boss by 20${\sim}$30%.

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A study on ECQV applied the butterfly key expansion algorithm (Butterfly key expansion 알고리즘을 적용한 ECQV에 관한 연구)

  • Sun, Seol-hee;Kim, Eun-gi
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • pp.762-764
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    • 2016
  • The ECQV(Elliptic Curve Qu-Vanstone) is a implicit certificate scheme based on ECC(Elliptic Curve Cryptography). Implicit certificates are smaller and faster than a traditional explicit certificate. Therefore, it can be used in a memory or bandwidth constraint communication environments. Also, the butterfly key expansion algorithm is a method to issue many certificates by using only one public key. In this study, by applying the butterfly key expansion algorithm to ECQV, we suggest a new useful issuing certificate method that can be used in vehicular communication environments.

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Flow Characteristics of Cryogenic Butterfly Valve for LNG Carrier (Part 2 : Flow Characteristics under Cryogenic Condition) (LNG선용 버터플라이밸브의 유동특성에 관한 연구 (제2부 : 극저온에서의 밸브 유동특성))

  • Kim, Sang-Wan;Choi, Young-Do;Kim, Bum-Suk;Lee, Young-Ho
    • The KSFM Journal of Fluid Machinery
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    • v.11 no.2
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    • pp.20-28
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    • 2008
  • Recently, butterfly valves are used as control valves for industrial process. However, there are not so many reports on cryogenic butterfly valves in spite of broad application in LNG storage station and LNG carriers. Present study is focused on the investigation of the detailed hydrodynamic and aerodynamic characteristics of cryogenic butterfly valves to contribute to the operation during the handling on LNG transportation system, and to the practical utilization in design of butterfly valves and actuators. The results show that large recirculation vortices in the region downstream of the valve are founded and the cavitation flows are intensively generated on the surface of valve disc at the relatively small opening angle. The aerodynamic characteristics, lift, drag and torque, acting on the valve disc are calculated. The pressure distribution and the pressure loss coefficient of the cryogenic butterfly valve show almost similar pattern with those of the butterfly valve which is used on the normal temperature.

Optimization of Butterfly Valve's Disc Using the DACE Model Based on CAE (CAE에 기반한 DACE 모델을 이용한 버터플라이밸브 디스크의 최적설계)

  • Park Young-Chul;Kang Jung-Ho;Lee Jong-Moon;Kang Jin
    • Journal of Ocean Engineering and Technology
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    • v.20 no.3
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    • pp.96-102
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    • 2006
  • The butterfly valve has been used to control the switch and flux of fluid. While research about the characteristics of butterfly valve fluid have been done, study of the optimum design, considering structural safety, must keep pace with it. Thus, a method is proposed for an optimum butterfly valve. Initially, the stability of the butterfly valve, using FEM and CFD, is evaluated, and a variable is selected using the initial analysis results. Also, the shape optimization design is accomplished using the DACE model. In terms of research results, the experiment satisfied the objective and limitation functions.

Numerical Analysis of Flows in Butterfly Valves to Prevent Cavitation (공동 현상 방지를 위한 버터플라이 밸브의 유동장 해석)

  • Yoon, Joon-yong;Lee, Seng-jun;Kim, Eun-suk
    • The KSFM Journal of Fluid Machinery
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    • v.7 no.1
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    • pp.9-16
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    • 2004
  • A three-dimensional numerical analysis was carried out on incompressible flows in butterfly valves by using commercial FLUENT/UNS code. Characteristics of complex flows including cavitation effect were investigated for different valve disk angles. The butterfly-valves that had different disk angles and different disk shapes were compared with each other in detail. This study focused on the flow analysis in the conventional butterfly valve and the newly designed butterfly valve in order to prevent cavitation. The newly designed valve shows great improvement on performance and endurance.

Optimum seat design for the quadruple offset butterfly valve by analysis of variance with orthogonal array

  • Lee, Sang-Beom;Lee, Dong-Myung
    • Journal of the Korean Society of Marine Engineering
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    • v.38 no.8
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    • pp.961-967
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    • 2014
  • In onshore and offshore plant engineering, a broad use of pipe system have been achieved and accordingly related technologies has been developed especially in the field of flow control valves. The aim of this study is to suggest the quadruple offset butterfly valve for bi-directional applications which show equivalent operating torque characteristics of the triple offset butterfly valve. Seat design parameters for the quadruple offset butterfly valve are determined by the proposed method utilizing both ANOVA (analysis of variance) and the orthogonal array. Through additive model considering the effect of design parameters on seating torque, mean estimation is performed and thus its optimization results are verified by design of experiment results. The insight obtained from the present study is beneficial for valve design engineers to develop reliable and integrated design of the quadruple offset butterfly valve.

The Butterfly Community Dynamics at Mt. Midong, Cheongwon-gun, Chungcheongbukdo, Korea (충청북도 청원군 미동산의 나비군집모니터링)

  • Kim, Do-Sung;Yi, Hoon-Bok;Kwon, Yong-Jung;Woo, Myeong-Suk
    • Korean Journal of Environmental Biology
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    • v.25 no.4
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    • pp.319-325
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    • 2007
  • We monitored the butterfly community dynamics from March to October for the three years (2002, 2003, 2004). The study areas were consisted of the five sectors with pine forest (Pinus rigida) and mixed oak forests at Mt. Midong in Chungwongun, Chungchungbukdo, Korea. We found that the total numbers of butterfly species were 59 species and the total individuals were 1,513. There was no change the number of species (44 species) during the study period but the composition of species and the number of individuals were different such as 414, 561, and 538, respectively. The most abundant species were Minois dryas (25%) in 2002, Polygonia c-aureum (24%) in 2003, and P. c-aureum (22%) in 2004. On the contrary, the number of singleton species was 20 species in 2002, 15 species in 2003, and 15 species in 2004. We found that there was the seasonal difference in species composition of butterfly community. The species diversity of butterfly community was the highest at sector 4 and sector 5 and lowest at sector 2. Main reason of the butterfly dynamics was strongly supposed to the human activity. We could suggest that the butterfly monitoring study must be a good way to measure the change of butterfly habitats including anthropogenic activity and the natural disturbances.

Development of Natural Dyeing Pigments and Culture Goods with Useful Biological Resources - Research on Development of Tourist Souvenirs for Hampyeong Butterfly Festival - (유용생물자원을 이용한 천연염료의 개발 및 문화상품전개 - 함평나비축제를 위한 관광기념품 개발에 관한 연구중심으로 -)

  • Park, Mi-Ryung;Kim, Sang-Yool
    • Fashion & Textile Research Journal
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    • v.8 no.6
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    • pp.665-671
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    • 2006
  • This study is to develop tourist souvenir which designed image of butterfly, the symbol of Hampyeong Butterfly Festival, using natural dyeing product, the specialty of Namdo region. Results of market survey of tourist souvenirs for Hampyeong Butterfly festival showed that souvenirs of butterfly design sold in market which were not discriminated from that of general products and locality or characteristic of the region could not be exhibited. According to the results of market survey, design of souvenirs of Hampyeong Butterfly Festival is as follows; Butterfly pattern of hinge and Dangcho pattern are developed to graphic motive of modern sense with traditional beauty to make design which can be consumed by modern consumers in their actual life and then proper pattern is planned by combining, repeating and disassembling them. Such a pattern is applied to souvenirs like T-shirts, necktie and scarf to make tourists feel identity and unification of the festival visually. In addition, design of souvenirs was made to be coordinated with casuals. Therefore, visual factor could be extracted from Korean cultural heritages suitable to concept of local festivals and it is considered that ways of commercialization and development of traditional pattern suitable to consumers' demands can be suggested.

Flow Characteristics of Cryogenic Butterfly Valve for LNG Carrier (Part 1 : CFD Analysis and its Comparison with Experimentation) (LNG선용 버터플라이밸브의 유동특성에 관한 연구 (제1부 : CFD해석과 실험결과의 비교))

  • Kim, Sang-Wan;Choi, Young-Do;Kim, Jung-Hwan;Lee, Young-Ho
    • The KSFM Journal of Fluid Machinery
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    • v.11 no.2
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    • pp.13-19
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    • 2008
  • Butterfly valves are widely used as control valves for industrial process. For the definition of optimum configuration of the valve, wide range of related studies has been actively conducted in the case of working fluids of water or air under the normal temperature. Recently, internal flow and performance characteristics of cryogenic butterfly valve for LNG carrier take a growing interest in the field of research and development. Therefore, present study is aimed to investigate the internal flow and performance characteristics of the cryogenic butterfly valve because the study result for the valve can be hardly found at present. Part 1 of this paper describes the study result of a butterfly valve model under the condition of the normal temperature. Succeeding Part 2 of this paper will describe the internal flow characteristics of a cryogenic butterfly valve for LNG carrier. The results of Part 1 show that pressure loss coefficients and flow rate coefficients obtained by the present experiment and CFD analysis agree well each other. Moreover, internal flow visualization for the valve by CFD analysis and PIV measurement have revealed complicated flow patterns of the internal flow field in detail.

Effect of a Butterfly Valve on the Uncertainty of Flow Rate Measurement (버터플라이 밸브의 유량측정 불확도에 대한 영향)

  • Yoon, Seok-Ho;Lee, Jung-Ho;Yu, Cheong-Hwan;Park, Sang-Jin;Chung, Chang-Hwan
    • The KSFM Journal of Fluid Machinery
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    • v.13 no.4
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    • pp.18-24
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    • 2010
  • For testing large-capacity pumps, the accurate flow rate measurement is needed in the test loop. As a measuring method of flow rate, venturi tube is recommended due to its low pressure loss. However, upstream disturbance of loop component such as a valve has an effect upon the accuracy of flow rate measurement. For controlling flow rate in case of high flow rate and large-scale piping system, a butterfly-type valve is generally used due to its compactness. However, a butterfly valve disturbs downstream flow by generating turbulence, cavities, or abrupt pressure change. In this study, the effect of downstream disturbance of butterfly valve on the flow rate measurement using a venturi tube is investigated. Test loop consists of circulation pump, reservoir, butterfly valve, venturi tube, and reference flow meter. The test is conducted with regard to a different valve opening angle of butterfly valve. According to the valve opening angle, the uncertainty of flow rate measurement is investigated.