[cen]

Hello, I am confused with the heat source Option Setting.
So my case is simulating a exothermic reaction. I set a heat sink value according to the reaction enthalpy in the energy source option of the region. (I didn't consider the reaction setting.)

But I am confused about the difference between total heat source, specific heat source and volumetric heat source.
I think for the same case,
total heat source = specifice heat source * mass flow rate * residence time
= volumetric heat source * volume.

But I got different results after ran those three cases.
Could anyone explains me the reason.
Thank a lot!!