Hi I am working on a similar problem, I downloaded your supplied mph file,
and rerun it. I basically plotted the bulk temperature which you had found,
in addition I chose different z planes in the fluid region and took the average using the comsol average function
and plotted these over the bulk temperature and in my case there seem to be some big discrepancies
between these methods, in the order of 20 degrees...
I would really like to know if you have been able to solve this problem, I have been working on forced convection problems to try to find heat transfer correlations on tubes and what I have been doing so far is taking around 20 z-plane cuts and averaging properties and calling them as the bulk property. I understand that in general bulk temperature, and other properties are defined in an integral sense so I do not know if this is why you chose the general projection function , in addition I also know this will make the job a lot easier than the way I have been doing it so far which is really time consuming and inefficient.
I do not know if you have resolved this problem, but it would be of great assistance if you have a model which has or some adaptation to this model you already uploaded.
Best
and rerun it. I basically plotted the bulk temperature which you had found,
in addition I chose different z planes in the fluid region and took the average using the comsol average function
and plotted these over the bulk temperature and in my case there seem to be some big discrepancies
between these methods, in the order of 20 degrees...
I would really like to know if you have been able to solve this problem, I have been working on forced convection problems to try to find heat transfer correlations on tubes and what I have been doing so far is taking around 20 z-plane cuts and averaging properties and calling them as the bulk property. I understand that in general bulk temperature, and other properties are defined in an integral sense so I do not know if this is why you chose the general projection function , in addition I also know this will make the job a lot easier than the way I have been doing it so far which is really time consuming and inefficient.
I do not know if you have resolved this problem, but it would be of great assistance if you have a model which has or some adaptation to this model you already uploaded.
Best