Container Thermal Stability During Extrusion Process
Altair EmployeeContainer thermal stability is an important factor that influences the extrusion process and product quality. The temperature difference in billet could vary up to 150 °C. These large variations in temperature could influence material flow and product quality.
The non-uniform temperature at liner inner wall,
Determines how billet skin flows into profile during extrusion
Produces uneven expansion of liner resulting in backflow that can lead to press failure
Heating Elements: Heating elements are placed inside the container and used for maintaining a proper temperature.
Feedback Control: Monitor temperature at thermocouples and regulate heating elements. These two features are used to determine the time required to reach thermal stability (periodic state)
How to setup model:
- Setup model using Inspire Extrude as mentioned in Tutorial1 and have solver deck ready.
- Then create BCs for heating elements and add that information in solver deck. Lets say we want to define Heating element at location #1 as “HE1”
- Open GRF file and add heating element data block as shown below after MATASSIN END block.
BEGIN PROBLEMDATA
HeatingElement HE1 { ThermocoupleName = "TC1" OnOffTemperature = 380 HeatFluxRampUpTime = 10 HeatFluxRampDownTime = 5 TemperatureTolerance = 1 }
Thermocouple TC1 { Location = -0.536 182.18 -250.0 }
END |
- ThermocoupleName : Specify the name of the thermocouple. This is defined in the next block
- OnOffTemperature : Specify the temperature at which the thermocouple should turn on and off. Here the value is 380 °C, which means this thermocouple will turn on when temperature falls below 380°C and turn off if the temperature goes above 380°C
- HeatFluxRampUpTime : Time needed to ram up the heating when the temperature falls below OnOffTemperature
- HeatFluxRampDownTime : Time needed to ram down the heating when the temperature goes above OnOffTemperature
- TemperatureTolerance : If tool temperature at a specified thermocouple location is within this tolerance then the thermocouple will active. This is to avoid numerical oscillation if temperatures is not exactly the same as OnOffTemperature.
- Location: X,Y, Z location of the thermocouple
- Now we will use this heating element information in one of BC as shown below,
ToolSurface TopFrontHE { IsHeatingElementPresent = "Yes" HeatingElementName = "HE1" X_Displacement = 0 Y_Displacement = 0 Z_Displacement = 0 HeatFlux = 7.5E4 #Material = Steel1010 } |
- IsHeatingElementPresent : Flag to specify is specific BC is heating elements of not
- HeatingElementName: Name of the heating element which has details about how it is going turn on and off