Dear COMSOL community.
I am new in COMSOL and I have some problems with my simulation. Mayby anybody could help me.
I try to simulate a heat exchanger. Steam is condensing on the outside. The heat is transfered through the tube to a cooling fluid inside the tube. For my problem I use the paper "On Teching Chemical Engineering Fundamentals Using FEMLAB" by William M. Clark.
In the attachement you can see my model. Given paramters are: geometry of the tube, temperature of condensate, temperature of incoming cooling fluid and velocity of the cooling fluid.
It consists of four domains: an inner cooling fluid, an estimated thermal boundary layer, the tube wall, and an estimated condensatefilm. The thermal conductivities of the two layers are determined by trial.
Now i would like to tell you my problems.
First i would like to scale my model in length. The real tube is 0.38 cm but i would like to simulate a 0.038 cm long tube without losing any information. So the fluid flow and the heat transfer must adapt to that scale.
The second problem i have is the biggest. I think the results of my simulation are false. As you can see in the attachement the temperature profile is not continouos. There is a jump in temperature between the fluid flow and the thermal boundary layer. But the aim is to have a continous temperature profil along the radius.
My last problem concerns to the results. I would like to determine the total heat flux along the tube. So I have to integrate the heat flux along the length but I do not know how to do it.
Maybe anybody can help me or anybody has a better idea to solve my problem.
A big thank to all of you!
Alex
I am new in COMSOL and I have some problems with my simulation. Mayby anybody could help me.
I try to simulate a heat exchanger. Steam is condensing on the outside. The heat is transfered through the tube to a cooling fluid inside the tube. For my problem I use the paper "On Teching Chemical Engineering Fundamentals Using FEMLAB" by William M. Clark.
In the attachement you can see my model. Given paramters are: geometry of the tube, temperature of condensate, temperature of incoming cooling fluid and velocity of the cooling fluid.
It consists of four domains: an inner cooling fluid, an estimated thermal boundary layer, the tube wall, and an estimated condensatefilm. The thermal conductivities of the two layers are determined by trial.
Now i would like to tell you my problems.
First i would like to scale my model in length. The real tube is 0.38 cm but i would like to simulate a 0.038 cm long tube without losing any information. So the fluid flow and the heat transfer must adapt to that scale.
The second problem i have is the biggest. I think the results of my simulation are false. As you can see in the attachement the temperature profile is not continouos. There is a jump in temperature between the fluid flow and the thermal boundary layer. But the aim is to have a continous temperature profil along the radius.
My last problem concerns to the results. I would like to determine the total heat flux along the tube. So I have to integrate the heat flux along the length but I do not know how to do it.
Maybe anybody can help me or anybody has a better idea to solve my problem.
A big thank to all of you!
Alex