heat tran-pdf教程aws_heat_transfer_110_ws08_W

1、Workbench-Simulation Heat Transfer 11.0Workshop 8 两平板间辐射(Ansys中的辐射建模)July 14, 2008 2008 ANSYS, Inc. All rights reserved.Inventory #002557 WS8-1Workbench-Simulation Heat Transfer ANSYS, Inc. Proprietary两平行平板间的辐射。 平板尺寸= 30 x 50 mm两平板间的距离S可变。 Q_plate = 2 W (每个平板)T_environment = 20 C(空间温度)所有热流最终都将辐射到空间中

2、。平板发射率= 0.10求解平板温度July 14, 2008 2008 ANSYS, Inc. All rights reserved.Inventory #002557 WS8-2Workbench-Simulation Heat Transfer ANSYS, Inc. Proprietary模型描述Workshop Supplemento (TQplate 1env = Qplate 2env- T44 )plateenv=Qplate1env(1-Aeplate ) + 1Fplateenv=1-Fplate 1plate 2AFplateplateenvplate (1+ X 2

3、)(1+ Y 2 )12 + X1+ Y 2 tan-1 Xln 1+ Y 21+ X2 + Y 22= pXY Fplate1 plate2 Y+ Y- X tan-1 X - Y tan-1 Y 2 tan-11+ X1+ X2with X = a/c and Y = b/c参考: /howell/sectionc/C-11.html可以从Qplate1 - env这个方程中求解TplateJuly 14, 2008 2008 ANSYS, Inc. All rights reserved.Inventory #002557 WS8-3Work

4、bench-Simulation Heat Transfer ANSYS, Inc. Proprietary理论解 Workshop Supplement 双击Twoplate.agdb第一个平面在XY 平面上。第二个平面位于平面Plane4上。 平面间距沿Z轴，由参数 “Spacing”定义。 July 14, 2008 2008 ANSYS, Inc. All rights reserved.Inventory #002557 WS8-4Workbench-Simulation Heat Transfer ANSYS, Inc. Proprietary几何 Workshop Supplem

5、ent 返回Project页 确认“parameter ”为空白，以便Simulation打开后能够读入 “Spacing” 参数。 建立新SimulationJuly 14, 2008 2008 ANSYS, Inc. All rights reserved.Inventory #002557 WS8-5Workbench-Simulation Heat Transfer ANSYS, Inc. Proprietary仿真 Workshop Supplement SpacingJuly 14, 2008 2008 ANSYS, Inc. All rights reserved.Invento

6、ry #002557 WS8-6Workbench-Simulation Heat Transfer ANSYS, Inc. Proprietary仿真模型 Workshop Supplement 这个问题的理论解建立在假设平板均匀热属性的基础上。对于这种情况，热导率 肯定非常高。默认时，两个平板是结构钢制成。编辑结构钢的材料属性，将热导 率增大到10,000 W/m-C。July 14, 2008 2008 ANSYS, Inc. All rights reserved.Inventory #002557 WS8-7Workbench-Simulation Heat Transfer ANS

7、YS, Inc. Proprietary调整材料属性 Workshop Supplement 建立辐射表面的命名选择 确保选择正确的表面 高亮 “back”，右击，选择 Create Selection Group ，将其命名为“innerback” 同样，将“前表面”设为 “inner front”July 14, 2008 2008 ANSYS, Inc. All rights reserved.Inventory #002557 WS8-8Workbench-Simulation Heat Transfer ANSYS, Inc. Proprietary辐射表面的命名选择 Worksho

8、p Supplement 选择New Analysis Steady State Thermal 在其上右击，插入辐射表面条件的命令。 Enclosure 1-Emissivity 0.1July 14, 2008 2008 ANSYS, Inc. All rights reserved.Inventory #002557 WS8-9Workbench-Simulation Heat Transfer ANSYS, Inc. Proprietary新分析 稳态热分析 Workshop Supplement 每个平板的外表面吸收2 Watts。July 14, 2008 2008 ANSYS,

9、Inc. All rights reserved.Inventory #002557 WS8-10Workbench-Simulation Heat Transfer ANSYS, Inc. Proprietary热载荷 辐射边界条件 (建立的简化方法)使用SF命令和命名选择为Enclosure 1 建立辐射边界条件。 Stefan-Boltzman 常数SI 单位 Hemiopt 命令 Outres 命令 确保为单元表保存单元信息 Rsurf 命令 使用辐射表面单元 July 14, 2008 2008 ANSYS, Inc. All rights reserved.Inventory #0

10、02557 WS8-11Workbench-Simulation Heat Transfer ANSYS, Inc. Proprietary添加命令行 Workshop Supplement 因为热导率很高，所以温度在两个平板之间变化不大。July 14, 2008 2008 ANSYS, Inc. All rights reserved.Inventory #002557 WS8-12Workbench-Simulation Heat Transfer ANSYS, Inc. Proprietary求解结果 Workshop Supplement 总共施加了4 Watts作为热载荷。 最终所

11、有的热量都传入空间中。 净辐射热流等于流入空间节点的热流。 流入平板的总体热量是：入射热通量面积+4 watts。 入射热量 反射热量+ 4 watts = 发射热量 下面幻灯片中的表格显示一些不同间距和发射率下的结果。July 14, 2008 2008 ANSYS, Inc. All rights reserved.Inventory #002557 WS8-13Workbench-Simulation Heat Transfer ANSYS, Inc. Proprietary结果解释 Workshop SupplementJuly 14, 2008 2008 ANSYS, Inc. Al

12、l rights reserved.Inventory #002557 WS8-14Workbench-Simulation Heat Transfer ANSYS, Inc. ProprietarySpacingEmissivityTsimulationTanalyticNet radiationEmittedReflectedIncident(m)(K)(K)(Watts)(Watts)(Watts).0031.0648.6645.43.90630.103-26.1970.5681.3666.23.94118.32914.38828.7760.1NC.0051.0578.7580.73.94519.071-15.1240.5614.8608.73.97512.1418.17116.3450.1764.8755.34.0005.81816.38318.201.0101.0511.7512.33.99911.669-7.6880.5553.3551.33.9927.9743.9807.9610.1729.87727.84.0024.2887.4278.253.