In this unit, we will perform a simple thermal and conductive simulation using the HEAT solver
to simulate ohmic heating in a wire.
The copper leads, aluminum wire and glass substrate are already setup in the simulation
It is important to make sure that the HEAT solver physics has been set to “thermal
Lets switch to partitioned volume mode to see how our simulation boundary conditions
Four sides of the simulation region have been assigned a constant temperature boundary condition
set to room temperature.
The top and bottom boundaries don’t have any boundary condition assigned so they will
be considered thermally insulating by the solver.
In addition, two voltage boundary conditions are added and have been assigned to the copper
leads to apply a voltage to the sides of the wire.
This has been done by selecting the “solid” surface type in the geometry tab for each
boundary condition and choosing the corresponding lead from the list of solids.
The left side of the wire will be swept from 0 to 1 volt in 6 steps by choosing the “range”
sweep type for the left voltage boundary condition.
The right lead will be kept at zero volt.
Lets run the simulation.
Next, right-click on the HEAT solver to visualize the 'thermal' dataset.
The 'thermal' dataset will provide the heat flow (labeled as Q) generated in the wire
as a function of voltage as well as the 3D temperature profile of the system as a function
To plot the heat generation and temperature profile on the plane where the wire is placed,
go to the chart settings and select 'clipped plane' from the Data Visualization options.
To see the change in heat generation or temperature as a function of voltage applied to the wire,
select “V_bias_left” from the list of parameters and use the slider to move between
different voltage values.
As in all thermal simulations, the ‘boundaries’ dataset from the HEAT solver provides the
physical area and the net power flow for each boundary of simulation.
In addition, when you run a thermal and conductive simulation, the electrical current passing
though voltage boundary conditions will also be reported in this dataset.
To view the current passing through the wire as a function of voltage, remove all the attributes
from the list except I_bias_left.
It can be seen that the current-voltage relation is linear as expected from a resistive device.
In fact, the resistance of the wire can be easily calculated from the inverse of the
slope of this plot which is 50 ohms.