• Title/Summary/Keyword: Separated Body

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Mixing Enhancement/Suppression of Separated-and-Reattaching Flow by an Upstream Small Object

  • IINVMA, Yusuke;FUNAKI, Jiro;HIRATA, Katsuya
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2004.03a
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    • pp.106-110
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    • 2004
  • Generally, flow around a bluff body such as a circular cylinder is complicated compared with that around a streamlined body because of the existence of separated shear layers. Long bluff body such as a flat blunt plate is more complicated than short bluff body, because of separated-and-reattaching flow on the after bodies.(omitted)

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Changing Effect in Aerodynamic Characteristics of a Captive Body Separated from Aircraft (항공기 탑재체의 분리 후 공력 특성 변화 효과)

  • Cho, Hwan-Kee;Lee, Sang-Hyun;Kang, Chi-Hang
    • Journal of the Korea Institute of Military Science and Technology
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    • v.14 no.3
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    • pp.397-404
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    • 2011
  • The aerodynamic characteristics of a separated captive body in flow field around aircraft are studied to observe aerodynamic stability for safe separation from aircraft. Since the captive body separated from aircraft is initially exposed to unsteady flow pattern, the change of aerodynamic forces and moments should be measured to analyze how the flow pattern affects on the captive body at the vicinity of aircraft. Aerodynamic forces and moments of the separated captive body are measured at selected positions along predictable dropping trajectories. The measuring trajectories, generated by the free drop test of the dropping model in the wind tunnel, are consisted of 9 possible lines by free dropped trajectories. Experimental results show that the aerodynamic forces and moments are significantly varied with the distance between the captive body and aircraft. In conclusion, the change of aerodynamic characteristics within flow field around aircraft should be considered to simulate trajectories of the separated captive body from aircraft.

Studies on the Utilization of Domestic Shale contained Chiastolite for Ceramics (국산 공정석함유 혈암의 요업적 개발에 관한 연구)

  • 정영기;오재현;이희수
    • Journal of the Korean Ceramic Society
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    • v.12 no.3
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    • pp.3-7
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    • 1975
  • The usefulness of the domestic shale contained chiastolite as additive were investigated. Crude mixed minerals were separated into shale and chiastolite. Refractory body added simple component or multiple components as additives was obtained when firing at 125$0^{\circ}C$ for each body. Compressive strength, refractories, apparent sp. gr., water absorption, corrosion test by slag, hot linear expansion were measured and X-ray diffraction analysis was observed. As the result of study, refractory body contained separated minerals as additives showed slightly increasing in refractoriness, lowering in sintering effect, the excellent effect for corrosion resistance by acidic slag. With more containing separated minerals, hot linear expansion for the body can be decreased.

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Motion Analysis of Two Floating Platforms with Mooring and Hawser Lines in Tandem Moored Operation by Combined Matrix Method and Separated Matrix Method

  • KOO BON-JUN;KIM MOO-HYUN
    • Journal of Ocean Engineering and Technology
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    • v.19 no.5 s.66
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    • pp.1-15
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    • 2005
  • The motion behaviors including hydrodynamic interaction and mechanical coupling effects on multiple-body floating platforms are simulated by using a time domain hull/mooring/riser coupled dynamics analysis program. The objective of this study is to evaluate off-diagonal hydrodynamic interaction effects and mechanical coupling effects on tandem moored FPSO and shuttle taker motions. In the multiple-body floating platforms interaction, hydrodynamic coupling effects with waves and mechanical coupling effects through the connectors should be considered. Thus, in this study, the multiple-body platform motions are calculated by Combined Matrix Method (CMM) as well as Separated Matrix Method (SMM). The advantage of the combined matrix method is that it can include all the 6Nx6N full hydrodynamic and mechanical interaction effects among N bodies. Whereas, due to the larger matrix size, the calculation time of Combined Matrix Method (CMM) is longer than the Separated Matrix Method (SMM). On the other hand, Separated Matrix Method (SMM) cannot include the off-diagonal 6x6 hydrodynamic interaction coefficients although it can fully include mechanical interactions among N bodies. To evaluate hydrodynamic interaction and mechanical coupling effects, tandem moored FPSO and shuttle tanker is simulated by Combined Matrix Method (CMM) and Separated Matrix Method (SMM). The calculation results give a good agreement between Combined Matrix Method (CMM) and Separated Matrix Method (SMM). The results show that the Separated Matrix Method (SMM) is more efficient for tandem moored FPSO and shuttle tanker. In the numerical calculation, the hydrodynamic coefficients are calculated from a 3D diffraction/radiation panel program WAMIT, and wind and current forces are generated by using the respective coefficients given in the OCIMF data sheet.

Effect of Isolation by Albumin Density Gradients on Head's Size of Bovine Sperm (Albumin density gradient 방법에 의한 고활력 우정자 분리시의 정자두부크기의 비교관찰)

  • Kim, Myung-Cheol;Jo, Chung-Ho;Chung, Soon-O
    • Clinical and Experimental Reproductive Medicine
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    • v.11 no.2
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    • pp.69-76
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    • 1984
  • In order to obtain high proportion of Y sperm the semen was laid over 6%,10% and 20% bovine serum albumin. Separated sperm were stained with quinacrine mustard in order to see F - body which could be seen in human Y sperm. But we could'nt find F-body in the bull sperm. So sperm were compared with size of sperm head. As a result of observation separated sperm was small in size of length and width of sperm head as compared with control sperm. So it was found that the proportion of Y sperm showed a marked increase in separated layer. Then the higher albumin density was, the higher the proportion of Y sperm which had smaller head and faster motility was. But the higher albumin density was, the lower the recovery rate of sperm was. So it was hard to separate Y sperm in oligospermia.

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Generation and Suppression of Non-uniform Flow in Scramjet Engines

  • Ben, Hidenori;Watanabe, Toshinori
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2004.03a
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    • pp.69-74
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    • 2004
  • In scramjet engines with sidewall compression inlet, it is well known that a non-uniform flow appears since a separated region is generated near the flow centerline on the body side. The separated region is caused by shock-boundary layer interaction and likely to cause un-start phenomena since the flow in the separated region is subsonic and acts as a communication path between the isolator and the combustor. In the present study, the non-uniform flow characteristics in the scramjet inlet-isolator region are numerically studied in detail. Effect of flow suction from body sidewall surface on the non-uniform flow field numerically examined to clarify the flow mechanism to suppress the un-start transition.

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Studies on the Composition of Amino Acid in Retina and Lens Body of the Frogs (개구리 망막체와 수정체의 Amino 산 성분에 관한 연구)

  • 강성호
    • The Korean Journal of Zoology
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    • v.2 no.2
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    • pp.10-14
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    • 1959
  • The retinae and the lens bodies of the frogs were hydrolyzed with 20% hydrochloric acid, and their amino acids were separated by paper chromatography. As a result of it the following were confirmed : (1) The retinae and the lens bodies were the same incomposition, and aspartic acid, glutamic acid, serine ,tyrosine, glycine, lysine arginine, threonine, alanine, histidine, proline, methionine, valine , phenylalanine, leucine, and two unknown substances were separated. (2) The free amino acids in the retinae were extracted with 80% ethyl alcohol and then separated by paper chromatography. Though their separation was not so definite , serine, gultaminc acid, and glycine were always separated regardless of the amount of the sample. When the amount of the smaple was enough , $\beta$-alanine , ${\gamma}$-amino butyric acid and methionine +valine were also separated. (2) The free amino acids in the retinae were extracted with 80% ethyl alcohol and then separated by paper chromatography. Though their separation was not so definite, serine, glutamic acid, and glycine were always separated regardless of the amount of the sample . When the amount of the sample was enough, $\beta$-alanine , ${\gamma}$-amino butyric acid and methionine + valine were also separated.

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Ownership of Human Biological Material - Concerning on Dead Body - (인체 유래 생물학적 물질의 소유권 - 사체를 중심으로 -)

  • Jung, Kyu Won
    • The Korean Society of Law and Medicine
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    • v.18 no.1
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    • pp.37-60
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    • 2017
  • Ownership is the bundle of rights that allow a person or institute to use and control an object. As the biomedical science is advanced, we should consider whether human biological material should be recognized as property. Whether separated parts of the human body can be objects of ownership is a different issue. Many thought that separated parts of the human body could not be objects of ownership. This idea is primarily based on this thought: even if a piece of human biological material is separated from a person, it still relates to that person, and if treated as a thing, human dignity may be harmed. However, some commentators have admitted separated parts of the human body into the realm of property. Though a person owns his/her body or body parts, this does not mean that he/she can do anything he/she desires. There are many natural and social limitations to exercise the ownership of human biological material as discussed above. Human dignity is the core consideration whether or not we recognize that ownership of human biological material biomedical research and knowledge.

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Large Eddy Simulations on the Configuration Design of Afterbodies for Drag Reduction (저항감소를 위한 물체후방의 형상설계에 관한 LES 해석)

  • PARK JONC-CHUN;KANG DAE-HWAN;CHUN HO-HWAN
    • Journal of Ocean Engineering and Technology
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    • v.17 no.5 s.54
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    • pp.1-10
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    • 2003
  • When a body with slant angle behind its shoulder is moving at a high speed, the turbulent motion around the afterbody is generally associated with the flow separation, and determines the normal component of the drag. By changing the slant angle of the afterbody, the drag coefficients can be changed, drastically. Understanding and controlling the turbulent separated flows has significant importance for the design of optimal configuration of the moving bodies. In this paper, a new Large Eddy Simulation technique has been developed to investigate turbulent vortical motions around the afterbodies, using slant angle. By understanding the structure of the turbulent flow around the body, the new configuration of afterbodies is designed to reduce the drag of body, and the nonlinear effects, due to the interaction between the body configuration and the turbulent separated flows, are investigated by use of the developed LES technique.

Large Eddy Simulations on the Configuration Design of Afterbodies for Drag Reduction (저항감소를 위한 물체후방의 형상설계에 관한 LES 해석)

  • Park, Jong-Chun;Kang, Dae-Hwan;Chun, Ho-Hwan
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2003.05a
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    • pp.49-55
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    • 2003
  • When a body with slant angle after its shoulder is moving at high speed, the turbulent motion around the afterbody is generally associated with the flaw separation and determines the normal component of the drag. By changing the slant angle of afterbody, there exists a critical angle at which the drag coefficients change drastically. Understanding and control of the turbulent separated flows are of significant importance for the design of optimal configuration of the moving bodies. In the present paper, a new Large Eddy Simulation technique has been developed to investigate turbulent vortical motions around the afterbodies with slant angle. By basis of understanding the structure of turbulent flaw around the body, the new configuration of afterbodies are designed to reduce the drag of body and the nonlinear effects due to the interaction between the body configuration and the turbulent separated flows are investigated by use of the developed LES technique.

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