• 제목/요약/키워드: Blending Surface

검색결과 170건 처리시간 0.024초

원형 고리와와 강체구의 상호작용에 의한 음향장 수치해석 (Numerical Simulation of Acoustic Field Interacting between a Vortex Ring and a Rigid Sphere)

  • 유기완;이덕주
    • 소음진동
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    • 제7권2호
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    • pp.215-222
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    • 1997
  • The flow and acoustic fields due to a vortex ring interaction with a rigid sphere are simulated numerically. The flow field is regarded as three-dimensional inviscid and incompressible. The vorticity is assumed to be concentrated inside the finite core of vortex filament. The vortex filament curve, described by parabolic blending curve function, is used to effectively solve the modified Biot-Savart equation. The interaction between a vortex ring and a rigid sphere using the parabolic blending curve is calculated. The trajectory of the vortex ring is obtained with several different initial positions between the ring and the sphere. The force variations acting on the sphere are calculated by using the boundary integral method. Finally, we can also obtain the acoustic signals at the far field observation positions from the force variations acting on the rigid surface. We can find that the dipole axis of the directivity patterns are rotated during the interacting phenomena.

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디젤 고압 분사 시스템에서 디젤-에탄올 혼합연료의 분무 및 미립화 특성에 관한 연구 (A Study on the Spray-atomization Characteristics of Diesel-ethanol Blended Fuels in a High Pressure Diesel Injection System)

  • 김세훈;박수한;이창식
    • 한국자동차공학회논문집
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    • 제18권3호
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    • pp.80-87
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    • 2010
  • The purpose of this paper is to analyze the effects of ethanol blending ratio and fuel temperature in diesel-ethanol blended fuel on the spray-atomization characteristics in a high pressure common-rail injection system. In this work, a diesel fuel and three blended fuels were used as test fuels. Blended fuels were made by blending ethanol with a purity 99.9% to diesel fuel, from 0% to 30%. In order to keep diesel-ethanol blending stability, 5% of biodiesel fuel as volumetric ratio was added into test fuels. The fuel temperature was controled in steps with 40K, from 290K to 370K. Macroscopic spray characteristics were investigated by analyzing the spray tip penetration and spray cone angle through spray images obtained from visualization system. In addition, in order to study microscopic spray characteristics of ethanol blended fuels, the droplet diameter, was analyzed using the droplet measuring system. It is revealed that the spray tip penetration is similar regardless of ethanol blending ratio. As ethanol blending ratio is increased, the spray cone angle becomes wider. It is shown that the spray cone angle is affected by low viscosity and density of ethanol. As the fuel temperature increases, the spray tip penetration and spray cone angle become shorter and narrower respectively. The SMD of ethanol blending fuels is smaller than that of diesel fuel because of low viscosity and surface tension of ethanol.

Evaluation of BR Blending Methods for ESBR/silica Wet Masterbatch Compounds

  • Kim, Woong;Ahn, Byungkyu;Mun, Hyunsung;Yu, Eunho;Hwang, Kiwon;Kim, Wonho
    • Elastomers and Composites
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    • 제52권4호
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    • pp.242-248
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    • 2017
  • Wet masterbatch (WMB) technology is studied to develop high-content and highly disperse silica-filled compounds. This technology refers to the solidification of surface-modified silica with a rubber solution or latex. Until now, researchs based on styrene butadiene rubber (SBR)/silica WMB has been mainly performed. However, the blending of SBR/silica WMB and BR is not known and is currently under research and development. Therefore, in this study, the BR blending method suitable for emulsion (ESBR)/silica WMB is investigated by measuring their cure characteristics and the mechanical and dynamic viscoelastic properties. As a result, it was confirmed that the blending of ESBR/silica WMB and BR/silica dry masterbatch is most appropriate. However, it showed a disadvantage compared with the conventional mixing method, which was due to the surfactant remained and the sulfuric acid used as the coagulant.

기하학적으로 정확한 쉘 요소의 NLib에 의해 생성된 NURBS 곡면에의 적용 (The application of geometrically exact shell element to NURBS generated by NLib)

  • 최진복;노희열;조맹효
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2005년도 춘계 학술발표회 논문집
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    • pp.301-308
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    • 2005
  • In this study, we implement a framework that directly links a general tensor-based shell finite element to NURBS geometric modeling. Generally, in CAD system the surfaces are represented by B-splines or non-uniform rational B-spline(NURBS) blending functions and control points. Here, NURBS blending functions are composed by two parameters defined in local region. A general tensor-based shell element also has a two-parameter representation in the surfaces, and all the computations of geometric quantities can be performed in local surface patch. Naturally, B-spline surface or NURBS function could be directly linked to the shell analysis routine. In our study, we use NLib(NURBS libraray) to generate NURBS for shell finite analysis. The NURBS can be easily generated by interpolating or approximating given set of data points through NLib.

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도공 안과의 혼합과 증점제의 특성과 도공지의 광택 발현성과 구조적 특성에 미치는 영향 (Effects of Pigment Blending and Thickener Characteristics on Calendering Response and Structure of Coated Paper-Effect of Pigment Blending on Coating Properties-)

  • 박종열;이학래;김병수;정현채
    • 펄프종이기술
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    • 제30권2호
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    • pp.62-73
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    • 1998
  • The aim of this work was to investigate the effects of pigment composition on the calendering response and structure of the coated paper. Calendering response of the coated paper was determined from the gloss values of the uncalendered and calendered coated papers, and the relationship between gloss and coating structure was discussed. The surface and cross section of the coating layer was observed using a scanning electron microscope to examine the coating structure. Coating layers were hardened in epoxy resin and polished with carbimet paper disc for preparing SEM samples. Maximum calendering response was obtained for the coated paper prepared from 80pph of clay and 20pph of ground calcium carbonate (GCC) as pigments. Photomicrographs of the surface and cross section of the coating layer show that clay tends to form dense coating structure, while GCC tends to form bulky coating layer.

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Monitoring and Optimization of the Effects of the Blending Ratio of Corn, Sesame, and Perilla Oils on the Oxidation and Sensory Quality of Seasoned Laver Pyropia spp.

  • Cho, Suengmok;Kim, Jiyoung;Yoon, Minseok;Yang, Hyejin;Um, Min Young;Park, Joodong;Park, Eun-Jeong;Yoo, Hyunil;Baek, Jeamin;Jo, Jinho
    • Fisheries and Aquatic Sciences
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    • 제18권1호
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    • pp.27-33
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    • 2015
  • Seasoned laver Pyropia spp. is one of the most well-known Korean traditional seafoods, and is becoming more popular worldwide. Various mixed oils are used in the preparation of seasoned laver; however, there is no information available regarding the effects of the blending ratio of oils on the quality of seasoned laver. In this study, the effects of the blending ratio of corn, sesame, and perilla oils on the oxidation and sensory quality of seasoned laver were monitored and optimized using a response surface methodology. An increase in the proportion of corn and sesame oils resulted in an excellent oxidation induction time, whereas a high ratio of perilla oil reduced the thermal oxidative stability of the mixed oil. In the sensory test, the seasoned laver with the highest proportion of sesame oil was preferred. The optimal blending ratio (v/v) of corn, sesame, and perilla oils for both oxidation induction time ($Y_1$) and sensory score ($Y_2$) was 92.3, 6.0, and 1.7%. Under optimal conditions, the experimental values of $Y_1$ and $Y_2$ were $4.41{\pm}0.3h$ and $5.58{\pm}0.8$points, and were similar to the predicted values (4.34 h and 5.13 points). Our results for the monitoring and optimization of the blending ratio provide useful information for seasoned laver processing companies.

과불소 아크릴 수성 폴리우레탄 복합체의 합성 및 물성 (Synthesis of Waterborne Perfluoroacrylic Polyurethane Composite and Its Property)

  • 유수용;김정두;문명준;감상규;이민규
    • 한국환경과학회지
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    • 제16권8호
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    • pp.865-872
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    • 2007
  • The waterborne perfluoroacylic polyurethane composite (WFPUC) series were prepared by the emulsion polymerization (WFPUC-E) and the physical blending (WFPUC-B). WFPUC-E was prepared by polymerizing perfluoroalkyl ethyl acrylate (FA) and waterborne polyurethane (WPU), and WFPUC-B was prepared by blending FA copolymer and WPU. The structures of the synthesized WFPUC were identified by using FT-IR-ATR. The surface and thermal properties of the synthesized WFPUC were investigated by measuring contact angle, surface energy, and TGA. The surface energy of WFPUC-E was lower than that of WFPUC-B. The thermal stability of the WFPUC-B showed better than that of the WFPUC-E.

다양한 표면개질을 이용한 폴리에테르설폰 막의 친수성 향상 (Enhanced Hydrophilicity of Polyethersulfone Membrane by Various Surface Modification Methods)

  • 박소정;황준석;최원길;이형근;허강무
    • 폴리머
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    • 제38권2호
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    • pp.205-212
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    • 2014
  • 본 연구에서는 폴리에테르설폰(polyethersulfone, PES)을 연소배가스에 포함된 수증기를 분리 및 회수하기 위한 고분자 분리막 소재로 사용하기 위해 다양한 물리 화학적 표면개질 방법을 사용하여 PES 평막 표면의 친수성을 향상시키고자 하였다. 균일한 PES 평막을 제조한 후 친수성 향상을 위한 개질 방법으로 산처리, 블렌딩 및 플라즈마 처리를 통해 표면개질을 하였고, 표면 특성을 비교하였다. PES 평막 표면의 특성 변화는 ATR-FTIR, XPS, SEM 및 접촉각 측정을 통해 관찰하였다. 황산을 이용한 산처리 방법과 양친매성 고분자를 이용한 블렌딩 방법에 의해 개질된 PES 평막에서는 접촉각의 변화가 크지 않았다. Ar 플라즈마 처리를 한 경우, 플라스마 처리 시간이 증가함에 따라 PES 표면의 친수성이 크게 증가하는 것을 확인할 수 있었다. 본 결과를 통해 다양한 표면개질 방법 중 플라즈마 방법을 적용하여 PES 표면을 처리하는 것이 PES 막 표면의 친수성 향상에 가장 효과적임을 확인하였다.

특징형상을 이용한 복합곡면의 설계 (A Feature-based Approach to Compound Surface Design)

  • 정재훈;김광수
    • 한국정밀공학회지
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    • 제12권2호
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    • pp.112-122
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    • 1995
  • While many surfaces such as automobile outer panels, ship hulls and airfoils are characterized by their smooth, free-form shapes, a far larger class of functional surfaces are characterized by highly irregular, multi-featured shapes consisting of pockets, channels, ribs, etc. In constaract to the design of aesthetic, free-form surfaces, functional surface design can perhaps best be viewed as a process of assembling a collection of known component surfaces to form a single compound surface. In this paper, we presents a feature-based functional surface modeling method. A single feature involves a secondary surface, which we must join to a primary surface with a smooth transition between two boundary courves. Through recursive blending of a secondary surface with the primary surface, the mullti-featured surface is represented. After constructing a compound surface, we generate the Z-map for NC machining of the surface. Offsetting the Z-map using the inverse offsetting technique, we get CL tool paths with out gouging.

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