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Hi all,

I am a new user with Comsol Multiphysics V5.6. Can anyone please help me with how to plot the Nusselt Number(Nu) v/s Reynold's Number(Re) line graph in Comsol for the tube bank problem I have attached to this query? I was able to model, mesh and apply appropriate physics and BC's to the same i.e., Turbulent flow, Heat Transfer in Fluids, Tube wall temperature and Inlet Velocity.

"The initial velocity, pressure, and temperature of the fluid were set at zero, atmospheric pressure and 298 K, respectively. Velocity-inlet and temperature-inlet conditions were imposed at the inlet of the computational domain. The velocity was varied from 5 to 15 m/s at the constant inlet temperature of 301.15 K. The temperature of the tube walls was fixed at 332.15 K. Outlet boundary condition was set at the exit with zero gauge pressure and zero gradients for other primitive variables. Wall functions were applied to the walls of the tubes and the channels".

I used a stationary solver setting for solving the problem. But, I am stuck in the post processing part. I need to find out the following from the simulation to find out the Nusselt Number: **Total convective heat flux, Qtotal **

If I get to know that, I guess I could easily calculate the average heat transfer coefficient, havg by dividing Qtotal with the temperature difference between the surface temperature of the walls of the tube bank and the upstream flow temperature.

Please correct me if I am wrong and suggest me the right way to approach this problem. Expecting your kind responses.

Thank You Rojo

Link to the paper is attached below:

https://www.researchgate.net/publication/332320584_Numerical_Study_of_the_Effect_of_Changing_Tube_Pitches_on_Heat_and_Flow_Characteristics_from_Tube_Bundles_in_Cross_Flow)