• Title/Summary/Keyword: CWC

Search Result 70, Processing Time 0.022 seconds

On the study for the Design Characteristics of the 60B2. Tyye among the Super High Speed Crafts (초고속 선형들 중 60B2형의 설계 특성에 관한 연구)

  • 구종도
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
    • /
    • 2001.05a
    • /
    • pp.93-102
    • /
    • 2001
  • 개발 목표로서, 최대 속도가 60knots인 초고속 단동 선형을 탄생시키기 위해서는 이 선형을 포함한 7척의 유사 선형들의 유체역학적인 성능에 대해 CWC에서의 모형선 시험과 computer simulation을 통해 계측값과 수치 계산값을 구하여 비교, 검토를 수행하였다. 그 결과, 60B2형이 모든 성능면에서 가장 우수하다는 평가를 얻었다. 그래서 본 논문에서는 이 선형의 설계 특성에 관해 기술하고자 한다.

  • PDF

Impact of Three Categories of Supplements on In Sacco Ruminal Degradation of Urea-Treated and Untreated Straw Substrates

  • Srinivas, Bandla;Krishnamoorthy, U.;Jash, Soumitra
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.15 no.2
    • /
    • pp.195-204
    • /
    • 2002
  • The objective of this study was to examine the impact of three categories of supplements on intake and diet induced difference on degradation of straw substrates. Sixteen crossbred cattle fitted with rumen cannula were randomly divided into 4 equal groups. Animals were fed on wheat straw ad libitum without any supplement except mineral mixture (control; $T_1$) or supplemented with concentrate mixture (CS; $T_2$) or green Lucerne (GLS; $T_3$) or urea-molasses block lick (ULS; $T_4$). Total dry matter intake in $T_2$, $T_3$ and $T_4$ was increased by 70, 54 and 49%, respectively compared to $T_1$ which was only 1.55 kg/100 kg B.Wt. Other than control animals, straw intake was less on $T_3$ than $T_2$ or $T_4$. In Sacco degradation of untreated and urea treated wheat or paddy straw in different treatments indicated that the supplements had a significant (p<0.01) impact on rapidly soluble (A) and insoluble but potentially degradable (B) fractions of straw. Urea treatment increased fraction-A but, provision of supplement improved fraction-B also. Effective degradation (ED) of OM was better on $T_2$. Rate of degradation (C) of OM and CWC was dependent on diet and type of straw but hemicellulose and cellulose were related to latter factor only. ED of cell wall carbohydrates (CWC) was similar in $T_2$ and $T_4$ but higher than $T_3$. CS was more effective in improving the degradation of both untreated and urea treated straw while ULS was effective on the former only. CS had more impact on superior quality straw while contrary was true with ULS. Although GLS improved intake and degradability of untreated and urea treated straws, its bulkiness affected the straw intake compared to other supplements.

The development of basic structure of jellyfish separator system for a trawl net (트롤어구용 해파리 분리 배출장치 기본 구조 개발)

  • Kim, In-Ok;An, Heui-Chun;Shin, Jong-Keun;Cha, Bong-Jin
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.44 no.2
    • /
    • pp.99-111
    • /
    • 2008
  • The purpose of this study is to develop the jellyfish separator system(JSS) for reducing fishery damage by the increase of jellyfish in the sea area of Korea in summer. First of all, to find the optimum structure of a JSS, six types of JSS in trawl fishery were designed and manufactured, the underwater shape of JSS and the separating process by JSS were observed in the circulating water channel(CWC). And the field experiments were carried out in July and September 2004 in the southern sea of Korea. For the moving path of the jellyfish model in the CWC, in case that the model was larger than the mesh size of the separator net, it was guided toward the lower part of the separator net by the guiding net and discharged through the outlet. In case that the model was smaller than the mesh size of the separator net, some models which passed through the upper part of the guiding net were smaller than the mesh size of the guiding net and discharged through the outlet and most of the model which passed through the lower part of the guiding net moved to the codend passing through the separator net. According to the field experiment result, the optimum tilt angle of separator net was inferred $20^{\circ}$ that the discharge rate of jellyfish was higher than the other tilt angle of separator net and the optimum structure of JSS was inferred GS type(consists of guiding net and separator net) that the discharge rate of jellyfish was higher than S type(consists of separator net). It was demamded to carry out more study for the countermeasure to reduce loss of fish.

A Potential-Based Panel Method for the Analysis of Resistance Characteristics of a High Speed Catamaran (포텐셜기저 패널법에 의한 고속쌍동선의 저항성능 해석)

  • Kim, Y.G.;Rhyu, S.S.;Yoo, J.H.;Lew, J.M.;Hong, S.K.
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.34 no.4
    • /
    • pp.12-20
    • /
    • 1997
  • A potential-based panel method has been developed to investigate the resistance characteristics of a high speed catamaran advancing on the free surface. Normal dipoles and sources are distributed on the body surface while sources are distributed on the free surface. Linearised free surface conditions are used in the present analysis. To avoid the instabilities due to the velocity difference between inner and outer flow of a high speed catamaran, Kutta condition has been applied at the stern. Model test has been carried out not only to validate the numerical results but to confirm the capabilities of a CWC(Circulating Water Channel). It is believed that we can obtain the qualitatively reasonable results in the CWC. Computed results are compared with those of experiments and Insel's experimental values. Since the Kutta condition is applied at the stern, stable solutions are obtained at the high speed range. The present method, using linearised free surface conditions at the high speed range, seems to be a useful tool in the hull form design of a high speed catamaran.

  • PDF

Quality Characteristics of Sansapyun Prepared with Various Amounts of Sansa Concentrate Gelatinized with Chinese Water Chestnut Starch (산사농축액 첨가량에 따른 올방개 전분 산사편의 품질특성)

  • Shin, Soo-Jung;Yoon, Hye-Hyun
    • Culinary science and hospitality research
    • /
    • v.18 no.4
    • /
    • pp.199-208
    • /
    • 2012
  • The purpose of this study is to investigate the characteristics of Sansapyun prepared with various amounts of Sansa concentrate(0%, 5%, 10% 20%, 30%) gelatinized with Chinese water chestnut starch. The Moisture contents and pH values decreased with Sansa concentrate increased. The Hunter L value of Sansapyun significantly decreased(p<0.001), but a, b values increased with Sansa concentrate increased. The hardness, springiness, chewiness, gumminess, cohesiveness were the highest in the control sample(0%) and the adhesiveness was the highest in Sansapyun with 30% sansa concentrate. In the sensory evaluation, red color, sour flavor, fruity flavor, Chinese medicine flavor, Sour taste, Chinese medicine taste, brittleness, stickiness increased with Sansa concentrate increased. Sleekness, hardness, springiness, gumminess decreased with Sansa concentrate increased. Sansapyun prepared with 10% Sansa concentrate showed the highest acceptance score(p<0.001). In addition, this study showed the possibility of Chinese water chestnut starch which is less expensive and easily available as a good replacement starch for traditional mung bean starch to prepare Kwapyun.

  • PDF

Analysis Study on 32nd OPCW Proficiency Test Sample with GC-TSQ CI (GC-TSQ CI 분석법을 이용한 제32차 OPCW 숙련도 시험 시료 분석 연구)

  • Kim, Hyunsuk;Jung, Changhee;Lee, Yonghan
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.17 no.6
    • /
    • pp.828-835
    • /
    • 2014
  • GC-TSQ CI technique was applied for analysis of samples for the $32^{nd}$ OPCW proficiency test. Eight chemical weapon convention(CWC) related chemicals were identified by product ion mode analysis with GC-TSQ in the samples. Choice of specific precursor ion made it possible to supply selective total ion chromatograms(TICs) of target molecule. GC-TSQ CI anaylsis technique was useful method for chemical warfare agent verification because analysis selectivity was improved by choice of mother molecule as precursor ion and gave mass spectra.

A Study on the Initial Hull Form Development and Resistance Performance of a 45 Knots Class High-Speed Craft (45노트급 고속정의 초기선형 개발과 저항성능에 관한 연구)

  • KIM JU-NAM;JEONG UH-CHEUL;PARK JE-WOONG;KIM DO-JUNG
    • Journal of Ocean Engineering and Technology
    • /
    • v.20 no.1 s.68
    • /
    • pp.32-36
    • /
    • 2006
  • The initial hull form of a 100 tan, 45 knot class high-speed craft is newly developed. The resistance performances are investigated using a model test at high speed in a circulating water channel. The effect of the initial trim is studied together. Wave patterns are observed to clarify the relationship between the resistance performance and the wave characteristics. It can be found that the initial trim plays a role in increasing the resistance performance above a certain velocity.

An Experimental Study for Resistance Performance of Small Size Fishing Vessel (소형 연안어선의 저항성능에 관한 실험적 연구)

  • Jeong, Uh-Cheul;Park, Chan-Won;Kim, Do-Jung;Kim, Young-Jun;Matsui, S.
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
    • /
    • 2002.05a
    • /
    • pp.251-256
    • /
    • 2002
  • Resistance performance of small size fishing vessel is experimentally investigated to find out the effect of fore-body shape and trim for the better hull form development. The tests are performed for four different cases in the high speed circulating water channel(CWC). Wave patterns are observed together to investigate the relation between the resistance performance and the wave characteristics.

  • PDF

Study on Resistance Characteristics of 50-ft class CFRP Power Yacht (경량탄소섬유(CFRP) 소재 50피트급 파워요트 저항특성에 관한 연구)

  • Jeong, Uh-Cheul;Ryu, Cheol-Ho;Oh, Dae-Kyun;Hong, Ki-Sup
    • Journal of Ocean Engineering and Technology
    • /
    • v.28 no.6
    • /
    • pp.493-499
    • /
    • 2014
  • The resistance performances were studied for two 50-ft-class power yachts made of carbon fiber reinforced plastic (CFRP) with different hull form characteristics using model tests. The tests were carried out at a high-speed circulating water channel (CWC) for the 16–38 knot range. The total resistance, trim, and sinkage were measured, and the results were compared with wave patterns. The results showed that a chine position at the draft line had a strong effect on the planning performance and resistance performance in a certain velocity range.

Numerical Analysis of HAT Tidal Current Rotors (수평축 조류발전로터 성능실험의 수치적 재현과 연구)

  • Jo, Chul-Hee;Yim, Jin-Young;Lee, Kang-Hee;Chae, Kwang-Su;Rho, Yu-Ho;Song, Seung-Ho
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2009.06a
    • /
    • pp.620-623
    • /
    • 2009
  • 여러 해양에너지 중 유체의 빠른 흐름을 이용하는 조류발전은 서해안과 남해안에 적용하기에 적합하며 해양환경의 영향을 최소화 하면서 많은 에너지를 연속적으로 생산할 수 있는 장점이 있다. 조류발전에서 1차적으로 에너지를 변환시키는 로터는 조류발전시스템의 주요한 장치중의 하나로 여러 변수에 의해 그 성능이 결정된다. 블래이드 수, 형상, 단면적, 허브, 직경 등 여러 요소를 고려하여 로터를 설계하며, 설계정보와 실험데이터를 바탕으로 수치모델을 구현하여 실험에서 직접 계측할 수 없는 로터 주변의 유체현상 및 간섭영향 등을 예측할 수 있다. 본 논문에서는 변화하는 유속에 따른 HAT 로터의 시동속도, 회전수를 측정하여 로터 형상과 허브-직경비가 다른 로터의 성능을 고찰하고, 이를 수치모델로 구현하여 로터주변 유동변화를 연구하였다.

  • PDF