• Title/Summary/Keyword: 형상변화

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The Variation of Hydrologic Performance Characteristics for Small Hydro Power Plant with Rainfall Condition (강우상태에 의한 소수력발전소의 수문학적 성능특성 변화)

  • Park, Wan-Soon;Lee, Chul-Hyung
    • Proceedings of the Korea Water Resources Association Conference
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    • 2008.05a
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    • pp.1369-1372
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    • 2008
  • 소수력자원은 신재생에너지 중에서도 온실가스 배출량이 가장 적고 에너지밀도가 매우 높기 때문에 개발할 가치가 큰 청정부존자원으로 평가되고 있다. 강우상태의 변화는 Weibull분포의 축척모수와 형상모수를 인위적으로 변화시켜 소수력발전소의 설계인자들의 변화를 모사하였다. 분석 결과, 소수력발전입지의 수문학적 성능특성은 해당유역의 강우상태에 따라 변하는 것으로 밝혀졌다.

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A Study on Characteristics of Emissions in GDI Engine with Intake Swirl Variation (흡기스월 변화에 따른 GDI 기관의 배기특성에 관한 연구)

  • 채재우;차민혁;이상만
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2000.11a
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    • pp.207-209
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    • 2000
  • GDI(Gasoline Direct Injection) 기관은 전체적으로 희박한 영역에서 작동되기 때문에 저연비, 고출력화 및 배기유해가스 저감에 매우 유리하다. GDI 기관에 있어서 희박연소를 실현하고자 한 연구는 공기유동 강화방식, 연소실 형상의 최적화, 부실식 연소, 분사된 연료의 미립화, 흡기포트의 형상 변화, 운전조건 변화에 따른 분사전략의 변화 등 그 방식도 다양하며,$^{<1-5>}$ 최근엔 이러한 각 방식들의 장점들을 적절히 활용하고 이에 따라 각기 고유한 모델을 채택하여 접근하려는 시도를 하고 있다$^{<6>}$ . (중략)

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Optimal Design of Impeller according to Blade Shape Variation Using CFD Simulation (CFD를 이용한 블레이드 형상 변화에 따른 블로워 임펠러 최적설계)

  • Yu, Da-Mi;Kim, Semo;Jang, Hye-Lim;Han, Dae-Hyun;Kang, Lae-Hyong
    • Journal of Aerospace System Engineering
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    • v.13 no.1
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    • pp.29-37
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    • 2019
  • The objective of this study was to investigate the influence of the blade shape on the impeller performance, for design optimizing of the high airflow impeller. First, the quantity, angle, and length of blades, which are considered to have a large influence on the impeller performance, were selected as design variables. Then, 27 cases of impeller shapes were selected according to the design of experiment (DOE). To predict the conduct of the blower based on the selected impeller shape, flow analysis was performed using the immersed solid method of ANSYS CFX. In the CFD results, the highest airflow was expected in the impeller having a combination of 50 EA, $6^{\circ}$ and 5 mm. Finally, a blower with the original impeller shape and the optimized impeller shape was fabricated using a 3D printer, and the analysis tendency and experimental tendency were verified through experiments.

물리적 인간 기계 상호작용을 위한 근육의 기하학적 형상 변화를 이용한 상지부 움직임 예측

  • Han, Hyo-Nyeong;Kim, Jeong
    • ICROS
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    • v.16 no.3
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    • pp.34-39
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    • 2010
  • 근육 활성화시 나타나는 근육의 기하학적 형상인 단면적 변화를 움직임 의도 예측에 사용했다. 밴드 형태로 구성한 유연한 압전 케이블(flexible piezoelectric cable)을 이용하여 단면적을 측정하는 착용형 근육 활성도 측정 센서(pMAS, piezo cable muscle activation sensor)를 설계했고, 상완부에 적용하여 팔꿈치의 움직임을 예측했다.

Numerical Study of Turbine Blade Surface Gas Temperature with Various RPM and Blade Edge Shape (터빈 블레이드 회전수 변화와 터빈 블레이드 엣지 형상 변화에 따른 표면 가스온도 분포 해석)

  • Lee, In-Chul;Byun, Yong-Woo;Koo, Ja-Ye;Lee, Sang-Do;Kim, Kui-Soon;Moon, In-Sang;Lee, Soo-Young
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2008.05a
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    • pp.49-52
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    • 2008
  • The numerical analysis for gas temperature of turbine blade surface has been performed to investigate development of temperature with various blade edge shape. Two different types of the turbine which one is "Sharp" edge and the other is "Round" edge was modeled. Computations have been carried out several turbine rotational speeds in the range from 0 to 10,000 rpm for the each types of turbine edge shape. As a result, the more rotational speed of turbine increased, the more turbine blade's temperature decreased. It is also found that the surface temperature of turbine blades for sharp type edge were lower than the round type edge.

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Experimental Study of a Micro Turbo Jet Engine Performance and IR Signal with Nozzle Configuration (배기노즐 형상변화에 따른 마이크로 터보제트 엔진의 성능 및 적외선신호 실험연구)

  • Park, Gyusang;Kim, Sunmi;Choi, Seongman;Myoung, Rho-Shin;Kim, Woncheol
    • Journal of the Korean Society of Propulsion Engineers
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    • v.20 no.5
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    • pp.1-8
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    • 2016
  • Micro turbojet engine test and infrared signal measurement were conducted to understand the characteristics of the engine performance and infrared signal with the variants of the exhaust nozzle configuration. A cone type nozzle and five rectangle type nozzles which has aspect ratio from one to five were used for the experimental work. The results show that there are not much difference between cone and rectangle nozzles of the thrust and specific fuel consumption. However infrared signal from exhaust gas become smaller as increasing aspect ratio.

An Experimental Study on Fire Resistance Performance of Asymmetric Slimfloor Beam (단면형상 변화에 따른 비대칭 H형강 합성플로어 내화성능변화에 관한 실험적 연구)

  • Kim, Hyung-Jun;Kim, Heung-Youl;Park, Kyung-Hoon;Lee, Jea-Sung;Cho, Kyung-Suk
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.7-8
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    • 2010
  • The temperature development of a structural element is dependent on section factor, which is estimated as a ratio of the fire-exposed perimeter to the cross-section area. Hence, with the higher section factor, the faster temperature development of the section os observed. Composite beam member, partially embedded asymmetry H beam, has a good fire resistance to the cross-section. The study was intended to conduct with change with section factor. The experimental result of section type which the Slim Beam Floor is bottom flange reinforced method.

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Cavitation and Noise Characteristics of High-Speed Propellers with Geometric Variations (고속 프로펠러의 형상변화에 따른 캐비테이션 및 소음 특성)

  • Jong-Woo Ahn;Young-Ha Park;Il-Sung Moon;Ki-Sup Kim
    • Journal of the Society of Naval Architects of Korea
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    • v.38 no.3
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    • pp.23-30
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    • 2001
  • The cavitation noise of high-speed propellers was experimentally studied using new measurement device in KRISO cavitation tunnel. A series of cavitation noise tests were carried out for 6 propellers with various sections, loading distributions, and a different area ratio. From the experimental results, the noise characteristics for various cavitation patterns and the noise performance for a series of propellers were analyzed. These can be used for full-scale prediction study of the noise and optimum design of high-speed propellers.

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