NexGen casting simulation software

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NexGen casting simulation software

NexGen casting simulation software

Technical Articles
Apr 01,18

The all new Flow-3D Cast v5 from Flow Science is a major leap forward when it comes to metal casting simulation and process modeling.

The all new Flow-3D Cast v5 from Flow Science is a major leap forward when it comes to metal casting simulation and process modeling.

Casters will now be able to choose the process they want to simulate and the software will provide the appropriate process parameters, geometry types, and sensible defaults. This substantially simplifies the simulation setup. Additionally, Flow-3D Cast’s robust simulation engine and new tools for predicting defects provide insights that will shorten design cycles and reduce cost. Featured developments include thermal modulus and hot spot identification output for solidification simulations, filling defect tools for identifying trapped gases and predicting venting efficiency, and faster and more robust pressure and stress solvers.

The all new Flow-3D Cast v5 comes in suites that contain related processes. The permanent mold suite includes process workspaces such as gravity die casting, low pressure die casting (LPDC), as well as tilt pour casting. For each process, the user interface only displays what is relevant to that particular process. The sand casting suite includes processes such as gravity sand casting and low pressure sand casting (LPSC). The lost foam suite includes everything in the sand casting suite plus the lost foam process workspace. And the HPDC suite includes everything relevant to high pressure die casting including thermal stresses and deformations. Within each process workspace, sub-processes like filling, solidification, and cooling are neatly-connected simulations that run one after another, modeling the complete process from start to finish, just as a metal caster would do it on the shop floor. The user can expand the process to include steps like the complete movement and filling of the ladle by dipping it into the melt pool and transferring it to the shot sleeve or pour cup. For LPDC, the process engineer can model the pressurization of the crucible and the flow of metal into the mold.

WYSIWYN Process Workspaces

The What-You-See-Is-What-You-Need (WYSIWYN) process workspaces streamline the versatility of Flow-3D Cast for unmatched ease of use and extraordinary solver performance and accuracy. Much of the interface has been simplified by applying the WYSIWYN design principle and asking for only the information that the user needs to provide.

Process-driven workspaces that were introduced in Flow-3D Cast v4.2 have been extended to include permanent mold processes such as gravity die casting, low pressure die casting and tilt pour, and sand casting processes such as gravity sand casting, low pressure sand casting and lost foam. More process workspaces including continuous casting, investment casting, sand core making, and centrifugal casting are in the works.

Defect Prediction

Identify filling defects using particles

Identifying filling defects caused by entrapped gas has become even easier with Flow-3D Cast v5 using particles. Not only are defects much easier to identify, the computational cost of predicting them has been significantly reduced.

Void particles have been introduced to represent collapsed gas regions. Previously, collapsed gas regions would disappear from the simulation if they became so compressed that they could not be resolved in the numerical mesh. Void particles behave like small bubbles and interact with the metal via drag and pressure forces. Their size changes in response to the surrounding metal pressure, and their final location at the end of filling indicate a potential defect due to air entrainment and/or oxides.

Metal/wall contact time

Wall contact time is useful for identifying locations on the mold surface that have been exposed to metal longer than others. These regions may be more susceptible to erosion. Metal contact time reflects the amount of time metal has been in contact with solid components, e.g., sand, which may lead to microporosity because sand particles act as nucleation sites. The output for the metal contact time with individual solid components has been extended to include the contact time with all components. The calculation of the contact time is activated by selecting Wall contact time in the Output tab.

Solidification defect identification

The Thermal Modulus, which is commonly used for sizing risers, is now output from solidification simulations.

Hot spots

Another new output quantity, ‘Hot spots’ is useful in mold design for locating and sizing risers and identifying the potential for solidification-related defects. Hot spots indicate the last places to solidify. These are represented by particles and are colored by hot spot magnitude. Risers should be located where the hot spot magnitude is largest.

Porosity analysis tool

The new porosity analysis tool in FlowSight identifies porosity-related defects in real-world terms. Defects can now be identified by their net volume, largest linear extent, shape factor, and total count.

Arbitrary 2D clips

Arbitrarily-oriented 2D clips are useful for sweeping through a simulation to look for defects. Previously, the metal regions displayed on these clips extended into cells that were occupied by solid components. In Flow-3D Cast v5, these clips can show metal in open space (e.g., the casting part) only by selecting the option to hide components.

Intensification pressure

The intensification pressure specified in high pressure die casting simulations is now coupled to both macro- and micro-porosity models, resulting in a more realistic relationship between the formation and size of these defects and the magnitude of the pressure applied by the plunger.

Adjusting shrinkage porosity

A shrinkage adjustment coefficient has been added to allow the user to fine-tune the amount and size of shrinkage porosity without the need to modify the properties of the metal. The coefficient provides a simple way of dialing up or down the amount of volumetric shrinkage during solidification.

Gas pressure and venting efficiency

The last local gas pressure and venting efficiency have been added to the output of filling simulations to help the user identify filling defects and assist in designing the venting system in die casting. The gas pressure records the last void pressure in a cell before it is filled with metal, while the venting efficiency shows areas where placing vents would be most efficient for evacuating air from the cavity.

Databases

Databases of commonly-used information in casting processes reduce setup errors and improve the simulation workflow.

Configurable simulation monitor

An important but often painstaking task encountered when running simulations is monitoring them. With Flow-3D Cast, users can monitor typical simulation objectives such as:

Melt velocity at gates
Solid fraction in the mold
Minimum/maximum temperatures of the melt and mold
Temperature at various probe locations
Simulation diagnostics (e.g., time step, stability limits)

Plotting capabilities

The simulation manager now includes more plotting capabilities. Plots can be user-configured, and the configurations saved to a database for use in other simulations. Users can specify which history-data variables to monitor on the simulation runtime graphs and add multiple variables to each graph.

Conforming meshes

The conforming mesh capability has been extended so that an active computational region of an arbitrary shape can be defined. This is achieved using a new type of geometry component called meshing component that defines a region in the computational domain, spanning both open and solid volumes, which a mesh block can conform to.

Mesh blocks can also be selectively conformed to either cooling channels or cavity, allowing users to choose optimum resolution for these geometric objects. Conforming meshes can now be displayed on the FAVORize tab.

Summary views of components/cooling channels

The Flow-3D Cast v5 interface provides a compact view of the various geometry components in a casting simulation. Two new geometry summary views – the component summary view and the cooling channel summary view – provide flyout, table views of the geometry components and cooling channels so that users can quickly see the important settings at a glance and make changes if necessary.