• Title/Summary/Keyword: Optimum Plate Spacing

Search Result 18, Processing Time 0.022 seconds

Mixed convection heat transfer from vertically parallel and misaligned plates (수직 평판의 평행배열과 엇갈린 배열에서 혼합대류 열전달)

  • 김상영;정한식;권순석
    • Journal of the korean Society of Automotive Engineers
    • /
    • v.15 no.3
    • /
    • pp.68-74
    • /
    • 1993
  • The mixed convection heat transfer has been studied numerically for misaligned and parrallel arrays of two flat plates at 100.leg.Re.leg.700, 0.1.leg.B.leg.1.0, 0.2.leg.leg.PHI.$_{R}$.leg.1Gr=10$^{4}$ and Pr=0.71. For misaligned plates and parallel plates, the optimum plate spacings move to the narrow spacing as Reynolds number and .PHI.$_{R}$ increase and can be expressed by the correlation equations at Gr=10$^{4}$. The optimum plate spacings for parallel plates sharply move to the narrow spacing compared with misaligned plates. The maximum mean Nusselt number of parallel plates shows higher value than that of misaligned plates and can be expressed by the correlation equations at Gr=10$^{4}$.EX>.

  • PDF

Combined Convective Heat Transfer from Vertical Parallel Plates (수직 평행평판에서의 혼합대류 열전달)

  • 양성환;권순석
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.13 no.2
    • /
    • pp.299-306
    • /
    • 1989
  • The combined convective heat transfer from vertical parallel plates with constant temperature has been studied by numerical method. The governing equations for the system are solved by the finite difference method and successive over relaxation scheme for Re$_{L}$ = 50 - 500, Gr = 10$^{4}$, Pr = 0.7. Results for various plate spacings and plate lengths are as follows ; For various plate spacings, the mean Nusselt number increases and then decreases as the dimensionless plate spacing increases. The optimum plate spacing for maximum mean Nusselt number decreases with increasing Reynolds number and can be expressed as a function of Reynolds number. For various plate lengths, the mean plate Nudest number increases as the dimensionless plate length decreases and Reynolds number increases.

Horizontal pullout capacity of a group of two vertical plate anchors in clay

  • Bhattacharya, Paramita;Kumar, Jyant
    • Geomechanics and Engineering
    • /
    • v.5 no.4
    • /
    • pp.299-312
    • /
    • 2013
  • The horizontal pullout capacity of a group of two vertical strip plate anchors, placed along the same vertical plane, in a fully cohesive soil has been computed by using the lower bound finite element limit analysis. The effect of spacing between the plate anchors on the magnitude of total group failure load ($P_{uT}$) has been evaluated. An increase of soil cohesion with depth has also been incorporated in the analysis. For a weightless medium, the total pullout resistance of the group becomes maximum corresponding to a certain optimum spacing between the anchor plates which has been found to vary generally between 0.5B and B; where B is the width of the anchor plate. As compared to a single plate anchor, the increase in the pullout resistance for a group of two anchors becomes greater at a higher embedment ratio. The effect of soil unit weight has also been analyzed. It is noted that the interference effect on the pullout resistance increases further with an increase in the unit weight of soil mass.

Model studies of uplift capacity behavior of square plate anchors in geogrid-reinforced sand

  • Keskin, Mehmet S.
    • Geomechanics and Engineering
    • /
    • v.8 no.4
    • /
    • pp.595-613
    • /
    • 2015
  • An experimental investigation into the uplift capacity of horizontal square plate anchors in sand with and without geogrid reinforcement is reported. The parameters investigated are the effect of the depth of the single layer of geogrid, vertical spacing of geogrid layers, number of geogrid layers, length of geogrid layers, the effects of embedment depth, and relative density of sand. A series of three dimensional finite element analyses model was established and confirmed to be effective in capturing the behaviour of plate anchor-reinforced sand by comparing its predictions with experimental results. The results showed that the geogrid reinforcement had a considerable effect on the uplift capacity of horizontal square plate anchors in sand. The improvement in uplift capacity was found to be strongly dependent on the embedment depth and relative density of sand. A satisfactory agreement between the experimental and numerical results on general trend of behaviour and optimum geometry of reinforcement placement is observed. Based on the model test results and the finite element analyses, optimum values of the geogrid parameters for maximum reinforcing effect are discussed and suggested.

Mixed Convection Heat Transfer from Vertically Misaligned Isothermal plates (수직으로 엇갈린 등온평판에서의 혼합대류 열전도)

  • 권순석;김상영;박순업
    • Journal of Ocean Engineering and Technology
    • /
    • v.6 no.1
    • /
    • pp.52-61
    • /
    • 1992
  • The steady laminar mixed convection from vertically misaligned, isothermal plastes has been studied by numerical procedure. The governing equations are solved by the finite difference method using successive using successive over relaxation scheme at Re=100-800, $Gr=10^3-10^6$, Pr=0.71 and dimensionless plate spacings b/L=0.1-1.0. The plume interaction caused by the thermal interference of twoplates is observed. As Reynolds numbers increase, the optimum plate spacings are moved to narrow spacings at the same Grashof number and as Grashof numbers increase, to wide spacings at the same Reynolds number.

  • PDF

The Effect of the Interactive Flow on Convective Heat Transfer from two Vertical Isothermal Parallel Plates (수직 등온 평행 평판에서 상호작용 유동이 대류 열전달에 미치는 영향)

  • 김상영;정한식;권순석
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.16 no.4
    • /
    • pp.765-774
    • /
    • 1992
  • The effect of the interactive flow on convective heat transfer from two vertical isothermal parallel plates have been studied numerically by the finite difference method. The Reynolds number, Grashof number, the relative length, L$_{2}$/L$_{1}$, and the dimensionless plate spacing, b/L$_{1}$ are varied as parameters. In case of outside mean Nusselt number, left outside mean Nusselt numbers show same values as L$_{2}$/L$_{1}$ and b/L$_{1}$ increase, but right outside mean Nusselt numbers decrease as L$_{2}$/L$_{1}$ increases. The inside mean Nusselt numbers are constant at narrow spacings and increase at wide spacings as Grashof numbers increase. The optimun plate spacing on left inside mean Nusselt numbers is b/L$_{1}$=0.4 at Re=100 and b/L$_{1}$=0.3 at Re=200. For the right inside mean Nusselt number, the optimum plate spacings move to the narrow spacing as Reynolds numbers increase and L$_{2}$/L$_{1}$ decrease.

The Analysis of Optimum Design Parameters for a Flat-Plate solar Collector Through Computer Simulation (컴퓨터 시물레이션 에 의한 太陽熱 集熱器 의 最適設計 에 관한 硏究)

  • 조수원;김종보
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.8 no.1
    • /
    • pp.1-9
    • /
    • 1984
  • In the utilization of solar energy most often a flat solar collector is used for solar heating, system. Since solar energy is absorbed through this solar collector, it is considered to be a most important part in the whole solar heating system. The purpose of the present investigation is to evaluate the influence of varying design parameters for thermal performances of flat-plate solar collector. By analysing these parameters, optimum design of solar collector would become possible. Specification of the existing solar collector are utilized in calculation as a starting point. Analysis is carried out numerically for "Unit Solar Collector" which is composed of fin and tube. Among design parameters. such parameters as mass flow rate per unit area, tube spacing and fin thickness are selected as variables in the computer simulation model. Results are presented for thermal performances of flat-plate solar collector for each important design parameters, so that predictions become possible through numerical analysis without performing experiments whenever it is required. required.

Mixed convection from two isothermal, vertical, parallel plates (등온 수직 평판에서의 혼합대류 열전달)

  • 박문길;이재신;양성환;권순석
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.14 no.6
    • /
    • pp.1645-1651
    • /
    • 1990
  • The steady laminar mixed convection from two finite vertical parallel plates has been studied by numerical procedure. The governing equations are solved by the finite difference method and point successive over relaxation scheme at R3=100-1000, Gr=0-10$^{6}$ , Pr=0.71 and dimensionless plate spacing b/$\ell$=0.05-0.1. The plume interaction caused by the thermal interference of two plates is observed. As Reynolds numbers are increased, optimum plate spacings are moved to narrow spacings at the same Grashof number, and as Grashof numbers are increased, to wide spacings at the same Reynolds number.

Improvement of pavement foundation response with multi-layers of geocell reinforcement: Cyclic plate load test

  • Khalaj, Omid;Tafreshi, Seyed Naser Moghaddas;Mask, Bohuslav;Dawson, Andrew R.
    • Geomechanics and Engineering
    • /
    • v.9 no.3
    • /
    • pp.373-395
    • /
    • 2015
  • Comprehensive results from cyclic plate loading at a diameter of 300 mm supported by layers of geocell are presented. The plate load tests were performed in a test pit measuring $2000{\times}2000mm$ in plane and 700 mm in depth. To simulate half and full traffic loadings, fifteen loading and unloading cycles were applied to the loading plate with amplitudes of 400 and 800 kPa. The optimum embedded depth of the first layer of geocell beneath the loading plate and the optimum vertical spacing of geocell layers, based on plate settlement, are both approximately 0.2 times loading plate diameter. The results show that installation of the geocell layers in the foundation bed, increase the resilient behavior in addition to reduction of accumulated plastic and total settlement of pavement system. Efficiency of geocell reinforcement was decreased by increasing the number of the geocell layers for all applied stress levels and number of cycles of applied loading. The results of the testing reveal the ability of the multiple layers of geocell reinforcement to 'shakedown' to a fully resilient behavior after a period of plastic settlement except when there is little or no reinforcement and the applied cyclic pressure are large. When shakedown response is observed, then both the accumulated plastic settlement prior to a steady-state response being obtained and the resilient settlements thereafter are reduced. The use of four layers of geocell respectively decreases the total and residual plastic settlements about 53% and 63% and increases the resilient settlement 145% compared with the unreinforced case. The inclusion of the geocell layers also reduces the vertical stress transferred down through the pavement by distributing the load over a wider area. For example, at the end of the load cycle of the applied pressure of 800 kPa, the transferred pressure at the depth of 510 mm is reduced about 21.4%, 43.9%, 56.1% for the reinforced bases with one, two, and three layers of geocell, respectively, compared to the stress in the unreinforced bed.

Optimum Design for Longitudinal Strength Members of Double Hull Tankers with Central Long'l Bulkhead considering Buckling Thickness Requirement of Plate Panels based on Common Structural Rules (CSR기반 좌굴 두께 요건을 고려한 이중선체유조선의 종방향 구조부재의 최적설계 연구)

  • Jo, Young-Chun;Lee, Jung-Chul;Lee, Sang-Bock;Shin, Sung-Kwang;Jang, Chang-Doo
    • Special Issue of the Society of Naval Architects of Korea
    • /
    • 2011.09a
    • /
    • pp.117-126
    • /
    • 2011
  • The buckling assessment of plate panels described in common structural rules (CSR) is to be determined according to the buckling utilization factor with hull girder stresses calculated on net hull girder sectional properties. As the thickness requirement for the buckling assessment of plate panels is not explicitly given in CSR, a lot of time is spent to find the proper thickness of plate panels until reaching to an allowable buckling utilization factor. In this study, in order to reduce time and cost, the thickness requirement of plate panels satisfying buckling assessment was derived. The structural design system included with the thickness requirement for buckling assessment was developed. The system is called as Oil-tanker Automated Structural Investigation System (OASIS). The design result of longitudinal strength members using OASIS was verified by Nauticus Hull which is the rule scantling software of DNV. Finally, optimum design of a double hull tanker for the minimum weight using OASIS was presented.

  • PDF