Where codes about heat transfer between gas and wall?

[zxc]

Dear developer:
I try to output heat transfer between wall and gas,but I only find codes about caculate heat transfer between particle and fluid. Where codes about heat transfer between gas and wall?
Thank you very much!

[jeff.dietiker]

This is a boundary condition. Look for CALL BC_PHI (T_g ... in solve_energy_eq.f

[zxc]

hello,jeff.I want to caculate the heat transfer coefficient between tube and bed in figure1.

I have some questions about this:

1. In fluid phase energy governing equations,there are no term about the heat transfer between wall and fluid.Could it be that the heat transfer between the fluid and the wall is not taken into account in the calculation of the energy equation？

2.If I want to output the wall-fluid heat transfer or heat transfer coefficient,What should I do？

Thank you very much,Jeff.

[jeff.dietiker]

The heat transfer between wall and fluid occurs when the boundary condition is applied. It is not explicitly part of the governing equation. If you want to compute the wall-fluid heat transfer, you will need to compute the temperature gradient between the fluid cell and the wall cell. This will require coding and knowledge of the MFiX code and data, so it may take some time for you to get familiar with it.

[zxc]

Thank you,Jeff.See your answer I have some ideas.Can you help me to see if it is reasonble?

• In figure1,red dots represent the temperature of each cell.I output these temperatures by using vtk.Now I try to compute the temperature gradient between the fluid cell and the wall cell.The formula is as follows：

Then I can compute the heat transfer between wall and fluid.

• I have some problems about .Is it the average gas volume fraction of three cell with red dots?

• If I use this method to compute heat transfer from the wall to the fluid.Does it contain the particle-fluid-wall thermal conduction?

Thank you very much,Jeff.