total energy calculation of an axisymmetric model
 

I have created an axisymmetric model (in fluent) of a solid cylinder with a water tube passing through its centreline. The water tube cools down the solid cylinder. The boundary conditions have been set and the model runs properly.

What I need to do now is to calculate the thermal energy stored in the solid cylinder once the temperature distribution of it is known. I was trying to use surface and volume monitors to do this but I couldn't set up the parameters properly. Can anyone comment on this?