Hello,

I have a small time dependent problem: a fluid is brought into a channel in a chip (it does not flow, it is already present) at a temperature of 40 °C. I want to know the time it takes to cool down the fluid (by conduction through the chip material) from 40 °C to an equilibrium temperature. The chip is cooled by natural convection with air at a constant T=20 °C.

So this is only an energy dependent problem, but I have problems with defining the initial conditions. If I apply 40 °C as initial condition, then it is defined for fluid and chip, and my chip is initial at a lower temperature. How can I define those 2 different initial conditions for the fluid and the material? Do I need UDF's?

Thanks a lot in advance, Willy

You can define separate initial conditions with "patch"

Solve->Initialize->Patch

Hope this helps, and good luck, Jason