菜单
  

    Computational modeling and simulation
    In this study six baffles are placed along the shell in alternating orientations with cut
    facing up, cut facing down, cut facing up again etc., in order to create flow paths across the tube
    bundle. The geometric model is optimized by varying the baffle inclination angle i. e., 0°, 10°,
    and 20°. The computational modeling involves pre-processing, solving and post- processing.
    The geometry modeling of shell and tube heat exchanger is explained below.
    Geometry modeling
    The model is designed according to TEMA (Tubular Exchanger Manufacturers Asso-
    ciation) Standards Gaddis (2007), using Pro/E Wildfire-5 software as shown in fig. 1. Design
    parameters and fixed geometric parameters have been taken similar to Ozden et al. [4], as indi-
    cated in tab. 1.The 3-D model is then discretized in ICEM CFD. In order to capture both the thermal
    and velocity boundary layers the entire model is discretized using hexahedral mesh elements
    which are accurate and involve less computation effort. Fine control on the hexahedral mesh
    near the wall surface allows capturing the boundary layer gradient accurately. The entire geome-
    try is pided into three fluid domains Fluid_Inlet, Fluid_Shell, and Fluid_Outlet, and six solid
    domains namely Solid_Baffle1 to Solid_Baffle6 for six baffles, respectively. The heat
    exchanger is discretized into solid and fluid domains in order to have better control over the
    number of nodes.
    The fluid mesh is made finer then solid mesh for simulating conjugate heat transfer
    phenomenon. The three fluid domains are as shown in fig. 2. The first cell height in the fluid do-
    main from the tube surface is maintained at 100 microns to capture the velocity and thermal
    boundary layers. The discretized model is checked for quality and is found to have a minimum
    angle of 18° and min determinant of 4.12. Once the meshes are checked for free of errors and
    minimum required quality it is exported to ANSYS CFX pre-processor.
    Governing equations
    The 3-D flow through the shell-and-tube heat exchanger has been simulated by solv-
    ing the appropriate governing equations, eq. (1) to eq. (5). viz. conservation ofmass,momentum
    and energy using ANSYS CFX code. Turbulence is taken care by shear stress transport (SST)
    k-wmodel of closure which has a blending function that supports Standard k-w near the wall and
    Standard k-e elsewhere.In ANSYS CFX pre-processor, the various fluid and solid domains are defined. The
    details of the domains created with the corresponding fluid-solid & fluid-fluid interfaces are
    provided in tab. 2, respectively. The flow in this study is turbulent, hence SST k-w turbulence
    model is chosen. The boundary conditions are specified in ANSYS CFX pre-processor and then
    the file is exported to the ANSYS CFX. The same procedure is adopted for the other twomodels.
    Validation
    Simulation results are obtained for different mass flow rates of shell side fluid ranging
    from0.5 kg/s, 1 kg/s, and 2 kg/s. The simulated results for 0.5 kg/s fluid flow rate formodel with
    0° baffle inclination angle are validated with the data available in [4]. It is found that the exit
    temperature at the shell outlet is matching with the literature results and the deviation between
    the two is less than 1%.
    The simulation results for 0.5 kg/s mass flow rate formodels with 0°, 10°, and 20° baf-
    fle inclination are obtained. It is seen that the temperature gradually increases from 300 K at the
    inlet to 340 K at the outlet of the shell side. The average temperature at the outlet surface is
    nearly 323 K for all the three models. There is no much variation of temperature for all the three
    cases considered.
    The maximumpressure for models with 0°, 10° and 20° baffle inclinations are 94 .43,
  1. 上一篇:阀重量对于阀塔性能影响CFD模拟英文文献和中文翻译
  2. 下一篇:注塑模CAE技术英文文献和中文翻译
  1. 便携式电子硫化机效率英文文献和中文翻译

  2. 主轴自振式钻头的加工预...

  3. 沥青填充式伸缩缝英文文献和中文翻译

  4. 平行和分布式作业破碎机英文文献和中文翻译

  5. 双曲柄环板式针摆线齿轮...

  6. 质量有缺陷的滚动轴承振...

  7. Web2.0的网络广告模式英文文献和中文翻译

  8. 杂拟谷盗体内共生菌沃尔...

  9. 当代大学生慈善意识研究+文献综述

  10. 十二层带中心支撑钢结构...

  11. java+mysql车辆管理系统的设计+源代码

  12. 河岸冲刷和泥沙淤积的监测国内外研究现状

  13. 大众媒体对公共政策制定的影响

  14. 乳业同业并购式全产业链...

  15. 电站锅炉暖风器设计任务书

  16. 中考体育项目与体育教学合理结合的研究

  17. 酸性水汽提装置总汽提塔设计+CAD图纸

  

About

751论文网手机版...

主页:http://www.751com.cn

关闭返回