Question

Steady state heat conduction equation without heat generation

Answer 1

Steady state conduction is the form of conduction that happens when the temperature difference driving the conduction is constant, so that, the spatial distribution of temperatures in the conducting object does not change any further.

In general, during any period in which temperatures are changing in time at any place within an object, the mode of thermal energy flow is termed transient conduction or nonsteady state conduction.

Answer 2

Recognize that heat transfer involves an energy transfer across a system ... In the equation above we substitute the 6 heat inflows/outflows using the .... that there is no temperature gradient in the other two directions