[Tleja]

Hi everyone

I'm working for gas-solid in fluidized bed reactor.

My system description, I packed solid at the buttom of reactor, then i feed gas throughout the reactor with 400K of temperature gas feed. I also kept the wall temperature as constant value of 350K.

The result from this system, I can get the realistic temperature profile of solid and gas.

As my knowledge, The wall heat flux at the wall should be calculated from

Q=hw(Twall-Tg)

Q= wall heat flux;
***hw= heat transfer coefficient;
Twall= temperature at wall;
Tg= Temperature of gas at the first layer of cell from wall;

Can anyone let me know how fluent calculate heat transfer coefficient of each phases at the wall??

Best regard
Tleja

[oozcan]

heat transfer made by conduction or convection are always equivalent (e.g. medium-solid, solid-fluid,solid-solid- fluid-fluid) . So,that is, you say ''at the wall''you can get only one heat transfer coeff. That is forced-convective heat transfer coeff. Moreover, I could not get Tg. How could you know that that temp. is first layer of cell from wall. You could just give your model boundary conditions and you could get results in compliance with your mesh. You could not know it which temperature gradient has in first layer cell from the wall. Moreover, the equation is to be solved in ANSYS-Mechanical in this way but not FLUENT.

[LuckyTran]

Originally Posted by oozcan

Moreover, I could not get Tg. How could you know that that temp. is first layer of cell from wall.

There is a variable called something like wall temperature which actually gives you the fluid temperature of wall adjacent cells.

[Tleja]

Thank you so much for your kindly help

At the moment, i found out how to calculate convection at the near wall in ANSYS theory as

http://www.afs.enea.it/project/neptunius/docs/fluent/html/th/node99.htm#stdwf

This information is really good for me. I hope that will be useful for who is studying in heat transfer

Best regard
Tleja