MOLDFLOW Cooling Analysis Strategies
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Transcript of MOLDFLOW Cooling Analysis Strategies
Cooling Analysis Strategies
Cooling Analysis ObjectivesCooling Analysis Objectives
Cooling analyses are performed to determine (in part) Cooling line placement Minimum cycle time Minimum temperature distribution on cavity and/or core Minimum temperature distribution between cavity and
core Whether high thermal conductivity inserts should be
used
Analysis TypeAnalysis Type
Objectives determines are cooling analyses are run There are two analysis types
Manual analysis• A cycle time is input into the analysis• Best if there is a known cycle time• Best if the cooling layout is poor
Automatic analysis• Calculates the cycle time for you• Best for minimizing cycle time• Automatic analysis should not be run if the cooling layout
is poor, because cycle times will be extended.
Automatic AnalysisAutomatic Analysis
Cycle time is calculated by Making sure the part is 100% frozen
• 100% frozen is the default, but the value can be defined Average of mold surface temperatures (top and
bottom) for all elements is within 1°C of the target mold temperature
Mold temperature convergence tolerance Maximum number of mold temperature iterations Geometric influence
Analysis Advanced ParametersAnalysis Advanced Parameters
Geometry Influence Parameter (GIP)Geometry Influence Parameter (GIP)
Geometric influence option Automatic
• The software calculates the minimum number of surrounding elements required to produce accurate cooling results for each element, which is faster and requires less computing time.
Ideal• The calculation for each element takes
into account all other elements in the model
Automatic
Ideal
Geometry Influence Parameter (GIP)Geometry Influence Parameter (GIP)
How it is used
Geometry Influence Parameter (GIP) TipsGeometry Influence Parameter (GIP) Tips
Use default automatic setting unless an issue arises Good to use when optimizing water lines
Ideal should be used if going on to warpage Parameter can be used but not typically recommended
for warpage Automatic ~ GIP 10, so for large models you can set the
parameter lower• Reduces memory requirements but may affect accuracy of
results Set to a high number (20-30) if Ideal gives problems
Cooling Memory ErrorsCooling Memory Errors
ERROR 702270 Disk Space Free up more disk space for both job manger temp and
project directories Change GIP, especially if running Ideal If using a large model, change GIP to 6-10 Upgrade to higher amount of disk space
ERROR 700080 Memory (RAM + SWAP) Increase swap size
• Swapping to hard drive increases analysis time significantly• Watch CPU usage when swapping, normally under 10%
Upgrade to higher amount of RAM Try to lower element count
Remesh Convert Fusion > Midplane model
Fusion Thickness Change Issue Fusion Thickness Change Issue
MPI allow you to manually change element thickness properties Does not move mesh OK for Flow
Issue for cooling as solver (Boundary Element Method) relies partially on mesh location
Heat flux calculations do use thickness property Typically gives accurate results
This issue affects warp results Most accurate results obtained by making changes in
CAD and re-importing Fusion mesh
When to Run CoolingWhen to Run Cooling
Model part & mold Fill
Optimize filling of the part Balance/size feed system Possible packing
Cooling Minimize temp differences DON’T run filling as input to cool
Flow Optimize packing if necessary, Use cooling as input to Flow,
cooling may have strong influence on packing
Warp Determine type (midplane
only) Determine magnitude Determine cause Reduce warpage
ExerciseExercise
Run a cooling analysis on the dustpan Set inlets locations with
• Reynolds number 10,000• Water temperature 25º C
Run analysis with the following inputs• Mold surface temp: 40º C• Melt temp: 225º C• Mold-open: 5 sec• Inj + Pack + Cooling: Specified 15 sec• Geometry influence: Ideal
Run a second cooling analysis with Automatic IPC Compare the results from the two analyses
Results SummaryResults Summary
Automatic AnalysisSummary of Cavity Temperature Results =====================================Cavity temperature - maximum = 54.6 CCavity temperature - minimum = 29.4 CCavity temperature - average = 39.8 CAverage mold exterior temperature = 26.9 CCycle time = 66.0 s
Specified AnalysisSummary of Cavity Temperature Results =====================================Cavity temperature - maximum = 91.2 CCavity temperature - minimum = 35.6 CCavity temperature - average = 59.0 CAverage mold exterior temperature = 29.2 CCycle time = 20.0 s
Target Mold Temperature 40º C
Specified analysisCycle time 20 sec.
Avg. cavity temp. 59.0ºC
Automatic analysisCycle time 66.0 sec.
Avg. cavity temp. 39.8ºCTarget mold temp. 40ºC
Top TemperaturesTop Temperatures
Max Temp 54.6 ºC
Maximum TemperatureMaximum Temperature
Max Temp 54.6 ºC
Manual analysisCycle time 20 sec.
Avg. cavity temp. 59.0ºCEjection temperature 107ºC
Automatic analysisCycle time 66.0 sec.
Avg. cavity temp. 39.8ºCTarget mold temp. 40ºC
Average TemperatureAverage Temperature
Manual analysisCycle time 20 sec.
Automatic analysisCycle time 66.0 sec.
Target mold temp. 40ºC
Max. Value 46.0º
Time to FreezeTime to Freeze
Manual analysisCycle time 20 sec.
Automatic analysisCycle time 65.6 sec.
Max. Value 15.7 sec
Coolant TemperatureCoolant Temperature
Manual analysisCycle time 20 sec.
Automatic analysisCycle time 65.6 sec.
Max. Value 26.0º
QUESTIONS?QUESTIONS?