The isotropic phase change material models can include the effects of a phase change from solid to liquid (melting) or from liquid to solid (freezing). Therefore, the analysis type must be transient heat transfer.
A material model with temperature independent properties and temperature dependent properties are available. The thermal conductivity and specific heat will be constant or entered in a spreadsheet as a table versus temperature depending on the chosen material model.
The mass density of a material is its mass per unit volume. Although the mass density of the real material may change when the part changes state from solid to liquid, there is no volume change in a heat transfer analysis. Therefore, the mass density is constant in the analysis; be sure to set it correctly based on the mass and volume of the part modeled.
This is the amount of thermal energy required to convert a unit mass of solid into liquid.
This is the temperature below which the part is completely solid. Raising the temperature above the solidus temperature will start to melt the part.
This is the temperature above which the part is completely liquid. Lowering the temperature below the liquidus temperature will start to freeze the part.
When working with an alloy consisting of a solute mixed in a solvent, the Melting Temperature of Solvent is the temperature at which the pure solvent changes from solid to liquid. This parameter is only used with the Scheil relation for calculating the liquid fraction. (See the equations in the paragraph Calculating the Liquid Fraction on the page Setting Up and Performing the Analysis: Thermal: Analysis Parameters: Transient Heat Transfer.)
When working with an alloy consisting of a solute mixed in a solvent, the Equilibrium Partition Coefficient is the fraction by volume of solute in the total alloy. This parameter is only used with the Scheil relation for calculating the liquid fraction.
The thermal conductivity of a material is a measure of the ability of the material to conduct heat. A material with a high thermal conductivity will conduct heat better than a material with a low thermal conductivity. A different conductivity is used for the solid state and liquid state of the part.
When the part is freezing or melting, the conductivity is a weighted average of the liquid fraction. Conductivity while freezing/melting = (conductivity of liquid)*(liquid fraction)+(conductivity of solid)*(1-liquid fraction).
When using a temperature-dependent property, the conductivity is entered in a spreadsheet as a lookup table versus temperature. The temperature range for the solid phase should extend at least from the minimum calculated temperature to the liquidus temperature, and the temperature range for the liquid phase should extend at least from the solidus temperature to the maximum calculated temperature. Keep in mind that due to the iterative nature of the solution, it is possible that the calculated temperature during some intermediate iteration may be outside of the final temperature range, so allow for some lead way when entering the properties.
The conductivity of an element is based on linearly interpolating the spreadsheet using the average calculated temperature of the nodes. If the slope of the conductivity-temperature curve is large or there are step changes in the curve, a small time step and/or small mesh should be used to capture the effect of the changing conductivity within the element. Enter the temperatures in ascending order (or use the Sort button after entering the data).
The specific heat of a material is the amount of energy required to raise the temperature of a single unit of mass of the material 1 degree. This property is applicable to all thermal elements. A different specific heat is used for the solid state and liquid state of the part.
When the part is freezing or melting, the specific heat is a weighted average of the liquid fraction. Specific heat while freezing/melting = (specific heat of liquid)*(liquid fraction)+(specific heat of solid)*(1-liquid fraction).
When using a temperature-dependent property, the specific heat is entered in a spreadsheet as a lookup table versus temperature. The temperature range for the solid phase should extend at least from the minimum calculated temperature to the liquidus temperature, and the temperature range for the liquid phase should extend at least from the solidus temperature to the maximum calculated temperature. Keep in mind that due to the iterative nature of the solution, it is possible that the calculated temperature during some intermediate iteration may be outside of the final temperature range, so allow for some lead way when entering the properties.
The specific heat of an element is based on linearly interpolating the spreadsheet using the average calculated temperature of the nodes. If the slope of the specific heat-temperature curve is large or there are step changes in the curve, a small time step and/or small mesh should be used to capture the effect of the changing specific heat within the element. Enter the temperatures in ascending order (or use the Sort button after entering the data).