I'm looking for help from any mathematician/scientist types out there with the following phrase:

**Loi de conservation du flux thermique selon**.

*x*The context is a work on applied mathematics. The phrase is an item in a list rather than being part of a full sentence.

My best attempt is "law of heat flow conservation in terms of x" or "...according to x". I'd be grateful if someone could confirm this is the right translation/suggest other alternatives if it isn't (maths is not my usual area...)

Thanks!