Cooling Channels
In die casting and permanent mold casting, cooling channels are drilled or cast into the die to extract heat from the mold and control the solidification of the casting. Their design has a direct impact on cycle time, die life, and casting quality. Too little cooling leads to hot spots, shrinkage porosity, and premature die failure. Too much or poorly placed cooling can cause premature solidification, cold shuts, and thermal fatigue cracking in the die.
The Cooling Channels model in FLOW-3D CAST simulates the thermal interaction between cooling circuits and the die across the full casting cycle, from filling and solidification through die opening, spray cooling, and the next fill. Engineers can evaluate channel placement, temperature setpoints, flow activation timing, and thermocouple control strategies to optimize thermal management before any tooling is cut.
Modeling Capabilities
The Cooling Channels model in FLOW-3D CAST supports:
- Time-dependent coolant temperature and heat transfer coefficients for each channel
- Independent activation schedules per channel, allowing selective cooling and heating at different stages of the cycle
- Thermocouple-controlled activation, where channels switch on or off based on measured wall or metal temperature at a user-defined probe location
- Both cooling mode and heating mode thermocouple control, supporting die preheating as well as active cooling
- Multiple channels with identical or different properties, each defined as separate geometry
- Full integration with thermal die cycling simulations for quasi-steady die temperature analysis over multiple cycles
- Integration with the Solidification Model and Microporosity Formation Model to assess the effect of cooling strategy on casting quality
- Visual cooling channel timeline showing when each channel is active alongside other process timings, added in 2024R1 to simplify setup and reduce input errors
- Moving components, such as sliders and plungers with cooling channels moves with them during motion.
How the Model Works
Rather than simulating the fluid flow inside each cooling channel, FLOW-3D CAST models the cooling effect using an effective heat transfer coefficient and coolant temperature assigned to the channel geometry. This approach is computationally efficient and accurate for the thermal management questions that matter most in casting process design. In practice, this means engineers can model complex multi-channel cooling systems, including conformal and conventional drilled circuits, without the added cost of full internal flow simulation, while still accurately capturing their effect on die temperature and casting solidification.
Each cooling channel can have its own temperature, heat transfer coefficient, and activation schedule, allowing complex real-world cooling systems to be represented accurately. Channels can be activated and deactivated at specified times during the cycle, or controlled automatically by thermocouples that monitor wall or metal temperature at defined probe locations in the die.
Shrinkage void regions with cooling channels (left) and without cooling channels (right), showing how thermal management directly affects shrinkage location and volume.
Thermal Die Cycling
Cooling channel design is most meaningful when evaluated over many casting cycles, not just a single fill. FLOW-3D CAST’s Thermal Die Cycling capability simulates the die temperature over repeated cycles until a quasi-steady state is reached, with no fluid flow modeled during the thermal-only stages. Each cycle can be divided into up to five stages representing filling, metal cooling, casting removal, die preparation (spray cooling and cleaning), and die closed time before the next fill.
This allows engineers to determine whether the cooling system maintains the die within the desired temperature window cycle after cycle, identify hot spots that accumulate heat over multiple cycles, and evaluate the trade-off between cycle time and die temperature stability.
The Thermal Die Cycling model was redesigned with a simpler, more intuitive setup process that aligns with standard process sheets used in high pressure die casting. The TDC sequence now starts at the beginning of the filling stage, and treatment schedules can be defined on a part-by-part basis. Cooling channels and heating elements move with sliders, and the full sequence of stages, schedules, movements, treatments, and assembly steps is shown in a single overview dialog.
Applications
The Cooling Channels model is used across die casting and permanent mold casting applications to:
- Optimize cooling channel placement to reduce cycle time without compromising casting quality
- Identify and eliminate hot spots that cause shrinkage porosity or premature die failure
- Design thermocouple control strategies for consistent die temperature across production runs
- Evaluate the effect of coolant temperature and flow rate changes on die thermal balance
- Assess die life by predicting thermal fatigue risk from temperature gradients in the die
- Validate cooling system designs before committing to tooling, reducing costly design iterations
- Support die design for high-volume HPDC structural components where thermal management is critical