peteroznewman
posted this
12 February 2018

- Last edited 14 February 2018
Please tell me more about the wire material and the coil as a whole.

What is the total length of wire in the coil?

What is the diameter of the wire?

How many turns are in the coil?

Are all the coils planar (in one layer) or are the coils in multiple layers, and if so, how many?

What is the total resistance of the coil in Ohms?

How does the resistance change when the temperature goes up?

What is the voltage across the coil?

Is the circuit constant voltage or constant current?

**Transient Thermal Optimization Example Model**

I created a very simple model that you can play with to learn some of the capabilities of ANSYS Design Optimization. It is just a circular wire with a parameter for the diameter, the wire body has an internal heat generation parameter and a heat transfer film coefficient parameter. It solves in 4 seconds and I can plot the time history of the surface temperature.

When you add parameters to an ANSYS model, you get a Parameter Set block in the Project Schematic.

That lets you easily type in values and solve that model in a table format. Below are 16 trials where I just typed in the values I was interested in and clicked Update.

You provided some experimentally measured values.

If I take the temperature at 150 s = 46 C, 300 s = 54 C and 600 s = 62 C as target values, I can try to adjust the available parameters to match those targets.

An observation was that the Internal Heat Generation was a good parameter to adjust to get T600 to hit a target value of 62 C. I can do that by trial and error (or manually apply a bisection algorithm), or I can add a Direct Optimization block to the system.

Then I can tell ANSYS to search for the value of Internal Heat Generation that satisfies the objective that T600 = 62 C and it automatically searches, solving the problem 16 times to arrive at the value.

While that value satisfies T=600 target of 62 C, the T=150 value is 45.2 C so does not satisfy the target of 42 C, and that is where a two parameter optimization can be employed to vary the diameter and the internal heat to satisfy two objectives.

With two objectives, it has brought the T150 temperature on target, though the T600 has drifted off somewhat.

I hope these examples give you a taste for what is possible. There are many other tools in the Design Exploration toolbox, so I hope you try these out on your project.