Interface for 1D Thermal Model

The 1D thermal model is useful to predict temperature profiles for thin and thick section composite structures that are oven or autoclave processed. The model has three tabular inputs: the process conditions table, and top as well as bottom boundary condition inputs. Each input can be changed by editing the tables directly or using the slider bar on the bottom right.

The thermal boundary conditions can either be step (constant) or ramp inputs. The initial condition is considered a constant temperature at time = 0. Right clicking the boundary conditions tables brings up a number of options described below:

Add: Adds a new ramp or step temperature input. You can add a new step or ramp anywhere in the table (even within existing values). The new input is added under the selected row. If adding a step within an existing table the time for this new step is averaged between the previous and subsequent time step. If a time step is added at the end then additional time is added to the overall solution.

Delete: Deletes the selected row. The first and second rows cannot be deleted as this is the minimum number of steps needed to solve for temperatures.

(Note: The final time for both top and bottom boundary conditions is automatically set to the same value maximum time value irrespective of what changes are made by the user)

Fill: Fills the selected column with the same value. This is useful if you wish to assign a constant temperature of boundary condition to the top or bottom of the laminate. You cannot use this function on the time column.

Change Rate to: Changes from step to ramp temperature input, (and vice versa)

Equilibrate: Used to match boundary conditions on both sides of the composite. Depending on which table is selected,  equilibration is applied to the opposite table.

Boundary Conditions: Three options are available as a boundary condition: Perscribed, Convective or Insulated. The perscribed option sets the boundary temperature at the assigned temperature and assumes enough energy is input on the surface so as to maintain this temperature. Right clicking the convective option sets the heat transfer coefficient to zero where it can then be changed to a value. Insulated means no energy can enter or leave the boundary. This is also equivalent to assigning a symmetric condition at this boundary.

Additional values for heat transfer coefficient (hf) are also available that include 10W/m^K (~still air) , 50W/m^K (~ air at 10m/s), 400W/m^K (metal contact) and 2000W/m^K (immersion in water)

 

Switch Time Units: This option switches the time from minutes to seconds (or vice versa) This does not convert the values of time, just the unit definition. This will convert time for both boundary conditions.

Change time to: This option converts time from minutes to seconds and vice versa. This conversion is done to both top and bottom boundary conditions to maintain consistency in the model.

You can interactively change any value by clicking that value and then using the slider bar on the bottom right. The range of this bar is affected by the value selected. For example clicking on a time value within any boundary condition will change the range from the time value at the previous step to the time value at the next step. You can manually override this range by clicking on the range values.