Introduction and Overview Extracting the input file Loading the input file into FLOW-3D Cast v

Transcription

1 Contents Introduction and Overview... 2 Extracting the input file... 2 Loading the input file into FLOW-3D Cast v Assigning definitions to geometry... 3 Required conversions... 4 Meshing and Geometry... 5 Temperature... 6 Physical Properties... 6

2 Converting SPF to prepin.inp Introduction and Overview In order to place FLOW-3D Cast version 4.0 onto a platform enabling modern programming techniques, libraries and IDEs, we have completely rewritten the graphical user interface. This change gives more flexibility and greater control to the user. A few notable advantages are the ability to use the recently released solver which generates a more concise results file, organization of projects and input files, use of a modern post processor and more. Going forward, this also means updates and enhancements to future releases can be done with better quality and in a more timely fashion. As a result of these changes, users of FLOW-3D Cast version who upgrade to FLOW-3D Cast version 4.0 will use a new format of input file in the form generated by FLOW-3D (named prepin.*). Also, version 4.0 will generate a results file that is no longer packaged into the.spf file upon simulation completion. For simulations run in v3.5.2, the new input file can be extracted but will require modification in order for it to be configured properly for v4.0. The following information is intended to guide customers through the conversion process. EXTRACTING THE INPUT FILE Upon completion of a simulation run in v3.5.2 a prepin.inp file is generated in a subdirectory below the folder the.spf file is stored in (refer to Figure 1). This input file can be opened in v4.0. The file, prepin.inp is the file generated that can be loaded into v4.0. Also required to be copied over are any.stl files in this subdirectory as they are referenced in the prepin.inp file. Figure 1 directory structure generated in FLOW-3D Cast v4.0 and the file generated within.

3 LOADING THE INPUT FILE INTO FLOW-3D CAST V4.0 It is first recommended to move the prepin file and the.stl s to a new directory. Then, create a workspace in FLOW-3D Cast v4.0 and load the prepin file. You will be prompted to give the file a name. What it is renamed to is how the new input file will be named. So, if the name Switch is given, that is what will show in the workspace. The actual file name will be prepin.switch. When the file is loaded there will be a dialog that opens showing all conversions made. These conversions will vary depending on the setup of the initial.spf file. Figure 2 is a sample of the report. Some conversions are correct but the file should still be reviewed to be sure the same models are activated and properly configured. There are also conversions that will have to be made due to the change in working units. More detail is provided in the REQUIRED CONVERSIONS section. Figure 2 Conversion report. ASSIGNING DEFINITIONS TO GEOMETRY In FLOW-3D Cast components and subcomponents use formal definitions in casting terminology. It is recommended as a first step before rescaling and changing physical properties to first give assignments to each item to be sure the geometry is defined properly. This is not required. However, if any new geometry is brought in then this step is necessary so in order to have a fully configured simulation ready for future modification. Figure 3 shows an example of geometry as defined when first loaded. FLOW-3D Cast requires that objects have formal casting related names as shown in Figure 4. To reassign, right-click on the subcomponents then redefine. In this example, Subcomponent 1 in Figure 3 is a solid primitive comprising a mold to fit the mesh extents. Change it to type Mold. It will require it be a new Component 2. Next, reassign the.stl file to be of type Casting Part and make it Component 2 also. The primitive is now a solid mold and the.stl is the cavity within it. Finally, component 1 can be deleted by right-clicking on it. When saving the GUI will reorder everything appropriately and there will only be a Mold and a Casting part.

4 Figure 3 Geometry (components) before redefining. Figure 4 Geometry (components) after redefining. REQUIRED CONVERSIONS The input file in FLOW-3D Cast v3.5.2 is created in CGS units (centimeters, grams, seconds) with temperature in Kelvin. In FLOW-3D Cast v4.0 the file must be in SI units (kg, meters, seconds) and temperature can remain in Kelvin or be changed to Celsius. Therefore, a number of properties will need to be manually changed.

5 Meshing and Geometry Because the units are now SI, all mesh extents and geometric definitions become the working units of SI when opening in FLOW-3D Cast 4.0. This means the geometry and the mesh must be rescaled by a factor of Geometry To rescale the geometry, choose details for each subcomponent as shown in Figure 5 and change the scale factor to Meshes For the meshing, each mesh block requires the gridlines be reduced to 1/100 th of their current location. Manually enter the new number. Note that the number of cells will remain the same so the resolution will automatically be correct. Figure 5 Scale factor applied to each subcomponent. Figure 6 Move the decimal two places to the left for each gridline of each block in each axis direction.

6 Temperature Temperature can be left in Kelvin or converted to Celsius. To convert, select the Units menu and then Temperature. Choose change and convert to automatically adjust all temperature settings (Figure 7). Figure 7 Changing temperature units. Physical Properties The last step in the conversion process is to change all physical properties. This includes properties for both fluids and solids such as density, viscosity, thermal conductivity, specific heat, heat transfer coefficients and boundary conditions if they are pressure, velocity or flow rate. This also applies to mass/momentum sources, vents and potentially more. The user should take care to be sure all values are correctly converted.