• 제목/요약/키워드: Dimple plate

검색결과 35건 처리시간 0.026초

딤플이 있는 판형 열교환기 관내측 열유동 최적화 (A numerical study for optimizing the thermal and flow performance in the channel of plate heat exchanger with dimples)

  • 이관수;시종민;정길완
    • 설비공학논문집
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    • 제11권5호
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    • pp.700-708
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    • 1999
  • The optimum dimple shape and arrangement in the channel of a plate heat exchanger with staggered dimples are proposed in this study. Four important geometric parameters are selected as design variables, the pressure drop and heat transfer characteristics are examined in the channel of plate heat exchangers. The optimization is accomplished by minimizing the global criterion function which consists of the correlations of Nusselt number and pressure drop. The optimum geometric parameters were found at the dimensionless dimple distance (L) of 0.272, the dimensionless dimple angle ($\beta$) of 0.44, the dimensionless dimple volume (V) of 0.106 and the dimensionless dimple pitch (G) of 0.195. It is found that the heat transfer and pressure drop of the optimum model are increased by approximately 227.9% and 32.9%, respectively, compared to those of the base model.

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딤플형 판형 열교환기의 유동 및 전열특성에 대한 수치해석 (A Numerical Simulation of Flow and Heat Transfer in a Dimple-type Plate Heat Exchanger)

  • 안혁진;이상혁;허남건;박형준;유해성
    • 설비공학논문집
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    • 제22권3호
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    • pp.149-155
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    • 2010
  • In the present study, the characteristics on the internal flow and heat transfer of the dimple-type plate heat exchanger were numerically investigated. For the numerical analysis, the conjugate heat transfer analysis between hot fluid-separating plate-cold fluid was performed using the periodic boundary condition at the center area of the plate and appropriate inlet and outlet conditions for the two streams. The numerical results were validated by the comparison with the experimental data. From these results, the correlations of the Colburn j-factor for the heat transfer and the Fanning f-factor for the flow friction were obtained. The present results could be applicable for the optimal design of dimple-type plate heat exchanger.

델타윙에 의한 이차유동이 딤플의 열/물질전달 특성에 미치는 영향에 대한 연구 (Investigation of heat/mass transfer coefficients in a dimple with upstream rectangular winglet pair)

  • 권현구;황상동;조형희
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회B
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    • pp.2029-2032
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    • 2008
  • In this study, we have investigated the effects of upstream rectangular winglet pair (RWP) on the heat/mass transfer coefficients in a dimple. Dimple print diameter was fixed at 20mm and the dimple depth was 4.0mm (0.4H). The dimple surface was coated with naphthalene for mass transfer experiment and the test plate was positioned at a rectangular straight duct whose aspect ratio (W/H) was 20. A rectangular winglet pair was positioned at y/d=-2.5. The RWP angle ($\beta$) was varied from $15^{\circ}$ to $60^{\circ}$. The Reynolds number, based on the duct height (H), was 5,000. with changing the RWP angle ($\beta$), the induced vortices had different flow characteristics; longitudinal or transversal vortices. These variation of induced vortices affected on the heat/mass transfer characteristics in the dimple.

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미세 딤플 가공 표면의 수력학적 윤활특성에 대한 수치해석 (NUMERICAL INVESTIGATION ON HYDRODYNAMIC LUBRICATION CHARACTERISTICS OF MICRO DIMPLE TEXTURED SURFACES)

  • 홍사훈;이재응;조민행;이성혁
    • 한국전산유체공학회지
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    • 제14권4호
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    • pp.56-61
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    • 2009
  • This study deals with the numerical investigation on two-dimensional lubrication characteristics of micro-dimple shapes fabricated on solid surfaces by using the commercial CFD code (Fluent V.6.3) to examine the influence of micro dimple depth and width on the reduction in friction under the sliding plate condition. In addition, single and multiple dimple arrays are simulated, all for a fixed area fraction of dimple on the surface. As a result, it is found that the existence of micro-dimpled surface makes it possible to substantially reduce the friction forces exerted on the surfaces, and such an optimum dimple depth would be present because the dimple depth larger than the optimum value did no longer affect the reduction in shear stresses, indicating that the reduction of friction is likely to be associated with inner flows of lubricant inside dimples. Moreover, it is observed that at the fixed area fraction, the friction reduction increases with the increase of dimple diameter.

미세 딤플 내부구조재 제작을 위한 롤 성형기술 연구 (A Study on Roll Forming Technology for Inner Structure Plate with Micro Dimple)

  • 제태진;김형종;김보환;허병우;성대용;양동열;최두선
    • 소성∙가공
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    • 제15권4호
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    • pp.326-332
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    • 2006
  • Sandwich structures, which are composed of a thick core between two faces, are commonly used in many engineering applications because they combine high stiffness and strength with low weight. Depending on the sheets by a rolling process, which is a more efficient and economical approach compared to other types of processes, has become an increasingly important subject of study. In this paper, we made a roll forming machine which progressive forming possible and force measurement for a roll forming of the sheet metal forming. And we designed a roll molding that arrayed of embossing size 3mm in diameter fabricate micro dimple inner structure plate. We carried out forming experiment such as array change and thickness to sts304 sheet. Ultimately, this research developed inner structure plate of high stiffness.

굽힘 하중을 받는 딤플형 금속 샌드위치판재의 최적설계 (Optimal Design of Metallic Sandwich Plates with Inner Dimpled Shell Subjected to 3-Point Bending)

  • 성대용;정창균;윤석준;양동열
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 춘계학술대회 논문집
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    • pp.702-705
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    • 2005
  • Metallic sandwich plates with Inner dimpled shell subjected to 3-point bending have been analyzed and then optimized for minimum weight. Inner dimpled shells can be easily fabricated by press or roll with high quality precision and bonded with same material skin sheets by resistance welding or adhesive bonding process. Optimized shape of inner dimple is a hemispherical shell to minimize weight without failure, including face yielding, face buckling and inner dimple buckling. It is demonstrated that bending stiffness of sandwich plate is 2 or 3 times than solid plates with same strength

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Experimental Study on Heat Transfer Performance of Absorber with Variable Plate Types

  • M.A. Sarker;Moon, C.G.;Lee, H.S.;Kim, E.P.;Yoon, J.I.
    • 한국에너지공학회:학술대회논문집
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    • 한국에너지공학회 2004년도 춘계 학술발표회 논문집
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    • pp.201-212
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    • 2004
  • An experimental study of the absorption process of water vapor into a lithium bromide solution was performed. For the purpose of developing high performance absorption chiller/hater utilizing lithium bromide solution as working fluid, it is important to improve the performance of absorber with the larger heat transfer area of the four heat exchangers. The experimental apparatus was composed of a plate type absorber which could increase the heat exchange area per unit volume to investigate more detail characteristics instead of the conventional type, that is, horizontal tube bundle type. The size of plate absorbers were made for 0.4m$\times$0.6m and the design objective of a refrigeration capacity was 1RT. In this experiment, three kinds of plate absorbers namely flat plate, dimple plate and groove plate were used. The obtained results were less than the design objective values, that is, the refrigeration capacity was about 0.3 ~0.4RT and the overall heat transfer coefficient was 500~600 kcal/$m^2$h$^{\circ}C$ at the standard conditions.

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플라스틱 판형 열교환기의 성능에 관한 실험적 연구 (An Experimental Study on the Performance of Plastic Plate Heat Exchanger)

  • 유성연;정민호;김기형;이제묘
    • 설비공학논문집
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    • 제17권2호
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    • pp.117-124
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    • 2005
  • Aluminum plate heat exchanger, rotary wheel heat exchanger, and heat pipe heat exchanger have been used (or ventilation heat recovery in the air-conditioning system. The purpose of this research is to develop high efficiency plastic plate heat exchanger which can substitute aluminum plate heat exchanger. Because thermal conductivity of plastic is quite small compared to that of aluminum, various heat transfer enhancement techniques are applied in the design of plastic plates. Five types of heat exchanger model are designed and manufactured, which are plate type, plate-fin type, turbulent promoter type, corrugate type, and dimple type. Thermal performance and pressure loss of each heat exchangers are measured in various operating conditions, and compared each other. Test results show that heat transfer performance of corrugate type, turbulent promoter type, and dimple type are increases about $43\%$, $14\%$, and $33\%$ at the equivalent fan power compared to those of plate type, respectively. On the other hand, the heat transfer performance of plate-fin type decreases $9\%$ because fins can not play their own role.

다양한 형상의 판형 열교환기 열전달 성능에 관한 해석적 연구 (Theoretical Study on the Heat Transfer Performance in the Various Type Plate Heat Exchanger)

  • 오재경;안성국;남상철;조홍현
    • 설비공학논문집
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    • 제24권8호
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    • pp.636-645
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    • 2012
  • The performance of various type plate exchangers with different chevron angle, dimple size and arrangement was analysed by using Ansys v13.0. Heat transfer performance, pressure drop and flow patten of plate heat exchanger were investigated according to mass flow ratio investigated and compared. As a result, the $60^{\circ}$-chevron type plate heat exchanger showed the highest heat transfer performance but pressure drop was relatively high. The efficiency of $45^{\circ}$-chevron type plate heat exchanger showed the best performance in considering of heat transfer performance and pressure drop simultaneously. Among dimple type plate heat exchangers, the highest heat transfer performance was shown in a dim_zigzag type plate heat exchanger but pressure drop was very high. Besides, the dim_upsize plate heat exchanger showed very low pressure drop.