What’s New – FLOW-3D CAST 2022R1
The new 2022R1 versioning of FLOW-3D products reflects Flow Science’s adoption of a synchronized release naming convention for FLOW-3D, FLOW-3D CAST and FLOW-3D HYDRO. 2022R1 represents the transition to a unified code base for FLOW-3D products. This important evolution will allow users access to the latest developments as soon as they are ready, at a more frequent product release pace.
FLOW-3D CAST 2022R1 features expanded controls for Active Simulation Control, tabular properties that allow users to easily understand complex dependencies without the need to fit data to a curve, and new outputs for identifying filling defects such as local filling velocity, time and temperature.
Expanded Controls for Active Simulation Control
Active Simulation Control (ASC) is very useful for controlling simulations based on flow information at probes. In this release, ASC now includes controls based on flow information from General History data, Flux Surfaces, and Sampling Volumes.
Investment Casting Example
- Metal source control (on/off) was based on probe-based data
- Metal source control can now be based on the fill fraction of the part volume: more robust control (not subject to splash)
- Termination condition can now be based on fill fraction of sampling volume
This video demonstrates Active Simulation Control being used to increase data output frequency when fast shot begins so that flow details can be captured. Flux surfaces are placed at the gates to measure the average velocity. When the average velocity exceeds 35 m/s, Active Simulation Control sets the output frequency to 0.0007 seconds for the duration of the simulation.
Material properties such as viscosity and surface tension are dependent on flow conditions such as temperature, strain rate, and possibly scalar quantities such as contaminants. Fitting these properties to functional forms requires complex curve fitting software, especially when the properties are dependent on more than one independent variable. The new tabular properties feature allows users to define these properties in table form with up to two independent variables, eliminating the need for curve fitting. For example, surface tension can be tabulated from experimental data to describe a complex, non-linear dependency on surface contaminants such as surface oxides as well as temperature. Additionally, viscosity can be tabulated from experimental data to represent a dependency on shear rate and temperature.
New Outputs for Identifying Filling Defects
Three new filling criteria outputs are available to identify potential casting defects caused by mold filling characteristics.
- Local filling velocity indicates the velocity of the melt when it first arrives at a particular computation cell. This output provides a single, summary view of the velocity map of the entire casting at the end of filling.
- Local filling time shows the time difference between when the melt first arrives at a particular computation cell and the last time melt arrives. Large differences indicate areas with a higher likelihood of filling-induced defects.
- Local filling temperature indicates the temperature of the melt when it first arrives at a particular computation cell. Low values of local filling temperature indicate areas where cold shuts are likely to occur.
VOF to Particles
The accuracy and robustness of the sharp-interface tracking VOF methods in FLOW-3D have been enhanced by combing them with fluid particles. The new particle species, called VOF particles, are used in place of the VOF function to track small fluid ligaments and droplets in the computational domain,
achieving better conservation of fluid volume and momentum. Higher time steps size can also be expected in gravity-controlled processes. The VOF fluid is automatically converted to VOF particles at certain times and locations when certain conditions are met. The particle motion is then calculated using the Lagrangian particle model and the particles are converted back to the VOF representation upon reentering the fluid.
Valves are commonly used in casting simulations to represent overflows in HPDC. Valves can now be controlled based on time. This feature is useful for representing valves in vacuum systems.
Deprecated Mold Temperature
Deprecated mold temperature now represents a more realistic system where new geometry temperature is driven by the type of object.