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Chapter 30. Reporting Alphanumeric Data

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Chapter 30. Reporting Alphanumeric Data Chapter 30. Reporting Alphanumeric Data ANSYS FLUENT provides tools for computing and reporting integral quantities at surfaces and boundaries. These tools enable you to find the mass flow rate and heat transfer rate through boundaries, the forces and moments on boundaries, and the area, integral, flow rate, average, and mass average (among other quantities) on a surface or in a volume. In addition, you can print histograms of geometric and solution data, set reference values for the calculation of nondimensional coefficients, and compute projected surface areas. You can also print or save a summary report of the models, boundary conditions, and solver settings in the current case. These features are described in the following sections. • Section 30.1: Reporting Conventions • Section 30.2: Creating Output Parameters • Section 30.3: Fluxes Through Boundaries • Section 30.4: Forces on Boundaries • Section 30.5: Projected Surface Area Calculations • Section 30.6: Surface Integration • Section 30.7: Volume Integration • Section 30.8: Histogram Reports • Section 30.9: Discrete Phase • Section 30.10: S2S Information • Section 30.11: Reference Values • Section 30.12: Summary Reports of Case Settings • Section 30.13: Memory and CPU Usage Reporting tools for the discrete phase are described in Section 23.7: Postprocessing for the Discrete Phase. Release 12.0 c ANSYS, Inc. January 30, 2009 30-1 Reporting Alphanumeric Data 30.1 Reporting Conventions For 2D problems, ANSYS FLUENT computes all integral quantities for a unit depth equivalent to 1 meter. This value can by adjusted to match the specific dimension of your application only by manually revising the Depth in the Reference Values dialog box (see Section 30.11: Reference Values). i The default value of Depth will be equivalent to 1 meter, even if the units are changed for depth in the Set Units dialog box (e.g., if the units for depth are changed to cm in the Set Units dialog box, the value of Depth in the Reference Values dialog box will be 100 cm). For axisymmetric problems, all integral quantities are computed for an angle of 2π radi- ans. 30.2 Creating Output Parameters You can create output parameters, which allow you to compare reporting values for different cases. These are single values generated by the four types of reports: • Fluxes (Section 30.3: Fluxes Through Boundaries) • Forces (Section 30.4: Forces on Boundaries) • Surface integrals (Section 30.6.1: Generating a Surface Integral Report) • Volume integrals (Section 30.7.1: Generating a Volume Integral Report) In the Reports task page, click the Parameters... button to open the Parameters dialog box, where a list of created input parameters and output parameters will be listed. The list of Input Parameters is available after performing the steps outlined in Section 7.1.9: Defining and Viewing Parameters. The list of Output Parameters is available after clicking the Save Output Parameters... button in the Fluxes, Forces, Surface Integrals, and Volume Integrals dialog boxes. You can define the output parameters either through the various reporting dialog boxes, as described in the sections that follow, or through the Create menu. In the Create menu, you will find a list of four items: Fluxes... Forces... Surface Integrals... Volume Integrals... 30-2 Release 12.0 c ANSYS, Inc. January 30, 2009 30.3 Fluxes Through Boundaries Selecting any one of these items will open their respective dialog boxes, where you will define the type of report you would like to generate. Details on how to generate the various reports are available in Sections 30.3, 30.4, 30.6.1, and 30.7.1. Once you have saved your output parameters, you can modify them by selecting the parameter in the Output Parameters list and clicking Edit.... This will open the report dialog box where you can make your changes. In addition, you can select any of the following under the More menu: Delete displays a message in a dialog box, prompting you for a response to confirm the deletion of the output parameter. Rename allows you to edit the name of the output parameter through the Rename dialog box. Print to Console reports values to the console window. If you select multiple output parameters, then the output includes values from multiple output parameters. Print All to Console outputs the values from all output parameters to the console win- dow. Write... allows you to store the output to a file. A dialog box is displayed allowing you to provide a file name. Write All... prompts you for a file name and then writes the values for all of the output parameters to a file. 30.3 Fluxes Through Boundaries This section contains information about generating a flux report. For more background information, see Section 20.1: Fluxes Through Boundaries in the separate Theory Guide. 30.3.1 Generating a Flux Report To obtain a report of mass flow rate, total heat transfer rate, total sensible heat transfer rate, or radiation heat transfer rate on selected boundary zones, use the Flux Reports dialog box (Figure 30.3.1). Reports −→ Fluxes −→ Set Up... Release 12.0 c ANSYS, Inc. January 30, 2009 30-3 Reporting Alphanumeric Data Figure 30.3.1: The Flux Reports Dialog Box 30-4 Release 12.0 c ANSYS, Inc. January 30, 2009 30.3 Fluxes Through Boundaries The steps for generating the report are as follows: 1. Specify which flux computation you are interested in by selecting Mass Flow Rate, Total Heat Transfer Rate, Total Sensible Heat Transfer Rate, or Radiation Heat Transfer Rate under Options. 2. In the Boundaries list, choose the boundary zone(s) on which you want to report fluxes. If you want to select several boundary zones of the same type, you can select that type in the Boundary Types list instead. All of the boundaries of that type will be selected automatically in the Boundaries list (or deselected, if they are all already selected). Another shortcut is to specify a Boundary Name Pattern and click Match to select boundary zones with names that match the specified pattern. For example, if you specify wall*, all boundaries whose names begin with wall (e.g., wall-1, wall-top) will be selected automatically. If they are all selected already, they will be deselected. If you specify wall?, all boundaries whose names consist of wall followed by a single character will be selected (or deselected, if they are all already selected). 3. Click Save Output Parameter.... The Save Output Parameter dialog box (Figure 30.3.2) will open where you will specify the name of the newly created output parameter, or overwrite an existing output parameter of the same type. The default report name format is report-type-n (e.g. flux-1). Figure 30.3.2: The Save Output Parameter Dialog Box After the output parameter is created, it is listed in the Parameters dialog box, accessed via the Parameters... button in the Reports task page. You can create any number of output parameters of this report type. 4. Click the Compute button to display the results of the selected flux computation for each selected boundary zone. The Net Results field will show the summation of the individual zone flux results. Release 12.0 c ANSYS, Inc. January 30, 2009 30-5 Reporting Alphanumeric Data Additional steps must be taken prior to generating a flux report for an interior boundary zone that has the same fluid defined on either side. In such a case, the area vectors of the cell faces associated with the zone may have been automatically defined in an inconsistent manner when the mesh file was read into the solver. Since the flux for each individual cell face is calculated with respect to its area vector, such an inconsistency leads to inaccurate results when the face fluxes are summed to calculate the total i flux of the boundary zone. To ensure accurate flux results for such an interior zone, you must orient the area vectors by changing the definition of the zone Type to wall. You should then change the Type back to interior and proceed to generate the flux report. Note that the fluxes are reported exactly as computed by the solver. Therefore, they are inherently more accurate than those computed with the Flow Rate option in the Surface Integrals dialog box (described in Section 30.6: Surface Integration). 30.3.2 Flux Reporting for Reacting Flows To report heat transfer for reacting flows, one of models in the Species Model dialog box must be enabled for the Total Sensible Heat Transfer Rate option to appear in the Flux Reports dialog box. For reacting flows, ANSYS FLUENT produces two kinds of reports which use a different treatment at the flow boundaries: • Total Heat Transfer Rate reports the total enthalpy flux, which consists of the total energy plus the species formation enthalpies. The heat rate based on this definition is a conserved quantity in reacting flows. See Section 5.2.1: Heat Transfer Theory in the separate Theory Guide for details. • Total Sensible Heat Transfer Rate reports the total energy flux as defined in Equa- tion 5.2-2 in the separate Theory Guide. Note that in reacting flows, this is not a conserved quantity and the addition or removal of heat due to the chemical reac- tions (Equation 5.2-10 in the separate Theory Guide) is reported separately in the Heat of Reaction Source field, as shown in Figure 30.3.3. If you have more than one reaction defined in your case, the Heat of Reaction Source reported is the sum of the heat for all reactions. For exothermic reactions the Heat of Reaction Source is reported as a positive quantity, while for endothermic reactions it will be a negative quantity.
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