FLOW-3D Cast v4

A major release, FLOW-3D Cast v4 provides you many new tools to improve your castings, including:

  • Thermal stress model to enable you to model stresses and deformations in solid and solidified parts in response to pressure forces
  • Multiple improvements to your ability to model cooling channels in your dies
  • Improved capabilities for modeling the generation of gasses from sand cores
  • Several new numerical options that enable faster simulation times
  • A new Simulation Manager function in the graphical user interface, allowing you to manage your simulations better, both before and as they run, and to visualize the progress of your simulations
  • Improvements to the user interface that make setting up your simulation much easier and more intuitive
  • A new state-of-the-art postprocessor, FlowSight™, capable of analyzing your results in ways that were not previously possible
  • Ability to run on the Linux operating system

Read more about this release in detail below.

Graphical User Interface (GUI)

Simulation Manager

FLOW-3D Cast Workspace

  • Portfolio: A Portfolio has been added to help organize groups of simulations. Simulations can be organized into workspaces allowing them to be run sequentially.
  • Templates: Templates can be created from a simulation and then used to create similar types of simulations, reducing setup time.
  • Runtime options: Ability to change many numeric settings while the simulation is running instead of having to terminate the simulation and start again. These options include pressure solver options, explicit and/or implicit option, general options such as number of processors.

Menu Options

  • Calculators: Thermal penetration depth calculator (default properties are for H-13), heat transfer coefficient calculator for cooling channels (default properties are water), and metal height in the shot sleeve calculator.
  • Update version or patches from GUI: This is an easy way to be informed if a patch is available and ready for download from the GUI.
  • Materials database: The material database has been redone for FLOW-3D Cast to include more properties as well as better navigation and material organization.

Model Setup

Cast 4 features a new innovative and intuitive Model Setup panel which greatly reduces the time required to create real simulations.  Users are guided through the simulation setup process by the logically arranged setup panels at the left side of the Model Setup window.  Elements of the casting process are entered by their actual names (e.g. mold, casting parts, filters) and appropriate physical models are activated automatically.

  • GUI organization: Improved process flow.
  • FAVOR™ checking: The FAVORizer is now equipped with a diagnostic tool for detecting poor mesh resolution of geometric objects defined using STL files. After running the FAVORizer to preview geometry, the results can be loaded into the graphical display window for interactive analysis.
  • Interactive baffle, history probe, pointer, and valve placement: A convenient new way of defining baffles, history probes, pointers, and valves was added for FLOW-3D Cast. It allows the interactive placement of these objects based on where a probe line intersects a component. The user can then choose two surfaces of a component and graphically locate a baffle, history probe, pointer, or valve between these surfaces.
  • Automesh: The ability to apply the total number of cells or the cell size to an entire mesh block will help make meshing easier to apply.
  • Units: Units are now in SI (kilograms, meters, seconds). There are two options for temperature: ºC and ºK.

Post-Processing

FlowSight

Visualizing HPDC results with FlowSight

Visualizing HPDC results with FlowSight

FlowSight is an advanced postprocessor capable of analyzing FLOW-3D Cast results in ways that were not previously possible. For example, FlowSight can:

  • Show multiple, time-varying plots of different data types at the same time to show big-picture and quantitative data to help explain your analyses to customers of different technical backgrounds.
  • Render results as a volume rather than a surface, allowing 3D images to show more information than is possible with an iso-surface.
  • Calculate complex new variables, like time averages and dimensionless parameters, based on user inputs.
  • Show fluid-structure interaction/thermal stress evolution results at the same time as fluid solution results.
  • Save and restore settings to make postprocessing standard images and animations faster and easier.
  • Make 2D slices through the domain in any direction (not just coordinate directions).
  • Allow users familiar with FLOW-3D Cast to continue to use FLOW-3D post-processing until they are comfortable with using FlowSight.

Solver

Meshing

  • Partially overlapping mesh blocks: The limitation that mesh blocks be purely linked or nested has been removed. Mesh blocks can now overlap each other in an arbitrary fashion. In areas common to several blocks, the flow equations are solved in the one with the finest mesh (based on the average cell size in the block); the solution is interpolated in all the other blocks. Partially overlapping mesh blocks make mesh generation less cumbersome and should generally result in fewer mesh blocks in a simulation.
  • Boundary conditions in nested blocks: When a nested block’s boundary coincides with an external boundary of the containing block, the user can define the standard boundary conditions at that nested block’s boundary, independently of those of the containing block. Previously, a nested block always assumed the boundary conditions of the containing block.
  • Solution sub-domains: The Unstructured Memory Allocation approach to addressing solution arrays on structured grids has been extended to have separate memory space (sub-domains) for the following types of numerical solutions: fluid flow, heat transfer in solid and core-gas flow. The result is a much more compact and efficient representation of the solution in memory, shorter simulation times and smaller results files. There is no input required from the user to take advantage of this development; the creation of the sub-domains happens automatically based on the geometry and model selection. There is also no loss of solution accuracy.

Casting Models

  • Core gas model: The accuracy of the core gas model has been enhanced through the introduction of the core gas solution sub-domain, which includes not only the fully blocked cells of a core gas component as in previous versions, but also the partially blocked ones. Also, the core gas model has been SMP parallelized.
  • Cooling channels: The versatility of the cooling channel model has been improved by treating cooling channels completely independent of the void model that was previously used to define cooling channels. Cells occupied by a cooling channel are still empty of solid and fluid material, but they are not included in the calculation of void regions. As a result, the reported void regions represent the actual physical voids in the problem. Also, a cooling channel can be connected to a void region and still retain its definitions and functionality as a cooling channel. Finally, when cooling channels are defined with STL files, those STL objects can be loaded in the 3D viewer and manipulated (e.g., hidden or made transparent) independently of the rest of the geometry.
  • Fluid-structure interaction (FSI) and thermal stress evolution (TSE) models: The FSI model describes fully- coupled interaction between fluid and solid using an finite element approach to model stresses and deformations in solid components in response to pressure forces from the surrounding fluid, thermal gradients, and specified constraints. The TSE model describes the evolution of stresses and deformations in solidified fluid region in response to temperature gradients and solidification. Stresses can be simultaneously computed in the mold and in solidifying metal with simple options for the interaction between them. The FSI model is also useful for those interested in modeling stresses on ejector pins.

General Purpose Models

  • Particle model:
    • Multiple initial particle blocks: Users can define multiple initial blocks of particles, so that particles can be introduced at the beginning of a simulation at different locations and with different properties.
    • Particle origin tags: Particles are now tagged according to their origin, indicating which initial block or particle source they came from. Separate tags are used for particle blocks and particle sources.
    • Mass particles: Particles can now be defined by density or diameter, they can have drag and diffuse, they can stick to solids or bounce off solids, and various other options.
  • Granular flows: The granular flow model has been extended from describing granular/gas mixtures to granular/liquid, or slurry, flows. This may be useful when modeling, for example, the flow of mud. The model can be viewed as a simple version of the sediment transport model without the complications of erosion and multiple sediment species. It uses the average grain properties to characterize the flow behavior of the granular material in the mixture. The forces acting on the granular media in both granular flow models, with gas and with liquid, now include dispersive pressure that arises from grain collisions in shearing flow. The additional force is a function of the  friction angle which is an input parameter to these models.
  • Liquid/Gas phase change: Initial and boundary conditions for the vapor/gas mixture can now be defined in terms of relative saturation. This is especially useful when modeling water vapor in air. Tabular and polynomial definitions of the P-T saturation curve and the latent heat as functions of temperature have been added to the liquid/gas phase model as an alternative to the existing Clausius-Clapeyron equation for the P-T curve and constant latent. This addition expands the applicability of the phase change model from the triple point temperature to the critical temperature. This model is useful for those who want to model core drying.

General Improvements

  • Tabular time-dependent input: Input tables for any time-dependent property such as mesh boundary conditions, GMO motions, or mass source rates, can now be defined using external files which are then read during the simulation without copying the data into the prepin file. Unlike the tables defined directly in the prepin file where the number of points is currently limited to 500, there is no limit on the number of time points in the external tables. This allows users to define very detailed behavior of transient objects in a simulation. The impact of using the external tables on the memory and CPU usage is very minimal.
  • Automatic fluid volume correction: An option has been added to automatically maintain a constant volume of fluid #1 to compensate for possible systematic volume errors due to severe distortion of free surface.
  • Implicit advection: The implicit advection solver has been enhanced to allow the user to define a threshold velocity or time-step size to directly control the use of explicit and implicit approximations of advective fluxes. The goal of this addition is to speed up simulations by maintaining a larger time-step size than in a fully explicit run, but small enough (based on the user’s judgment) to resolve the essential features of the flow.
  • Volume fraction cleanup: The volume fraction cleanup option allows users to force the preprocessor to close small openings between solid components that sometimes appear due to minor inaccuracies in the STL data. Barely open cells could pose problems for the stability of the flow solution, but at the same time are usually not important.
  • Fluid pointers: A pointer is used to fill all open cells within an enclosure with fluid.
  • Die temperatures: When using a reduced heat transfer solver inside solid components, i.e., the thermal penetration depth model or the constant non-uniform temperature option, the solid temperature in the solid region outside the active domain is now retained and can be used for post-processing and restarts. This is especially useful when running, for example, a thermal die cycling simulation with the full heat transfer solver, then a filling restart with a reduced heat transfer solver and then another restart simulation for solidification, again with the full heat transfer solver. In this case, the die temperatures obtained during the first simulation are available in the last one as the initial conditions in the newly activated die regions.
  • Hydrostatic mesh boundary conditions: A hydrostatic pressure boundary condition is primarily characterized by the fluid elevation. The hydrostatic pressure boundary condition has been extended from the x and y-direction mesh boundaries to the z-direction boundaries. When fluid elevation is defined at a ZMIN or ZMAX boundary, the uniform boundary values of fluid fraction and pressure are automatically computed.
  • Time-dependent void pointers: Void pointers can now be used to define not only an initial state of a void region, but also its pressure and temperature during the simulation by using tabular definitions of these parameters vs. time. This feature effectively acts as a time-dependent boundary condition for the fluid surrounding the void containing the pointer. A time-dependent pointer becomes inactive when covered by fluid or a GMO component, and is reactivated as soon as it becomes surrounded by void again. Time-dependent void pointers could be used to model heat treatment of a casting by defining the time-dependent temperature in the void surrounding the part.
  • Mass source and steady-state: Mass and mass/momentum sources are now compatible with the constant-velocity flow solver, IFVELP=1. This is useful when a fully transient simulation with mass sources/sinks is run first to achieve a steady-state at which point a restart simulation is carried out with the constant velocity field.
  • Component permeability input: Permeability can now be directly input to define porous properties of core gas, permeable mold and porous components. Non-Darcian permeability can also be defined for core gas and porous components (not for permeable mold components). The existing options to use sand grain size for the core gas and permeable mold, or drag coefficients for porous components have been retained.
  • Flow rate at valves/vents: Gas flow rate at valves is output to the General History data catalog. This is useful for the evaluation of the effectiveness of the gas evacuation at valves.
  • Output options: Output frequency of data as a function of time for history data, selected, restart, short prints, and long prints. History output is time dependent output of moving objects.