CFD Online Discussion Forums - Heat transfer from a heated plate using fins

Hi, we are simulating a simple heat transfer problem. The fins are supposed to enhance heat transfer from a plate. It consists of fins and air is being passed through them so as to cool them.

We guess that the design and mesh are correct, and perhaps we are not able to pre-define the problem. The description of our solving strategy is as follows:

1. Modelling in Pro-E
2. Importing in Ansys Workbench 14.0 Release, Fluid Flow (FLUENT)
3. DESIGN MODELLER: Creating Named Selections in Design Modeler, and specifying the domain as fluid and the fins as solid.
4. ANSYS MESH: Creating Fine Mesh with Default settings in Ansys Mesh.

5. FLUENT:
i. Creating Problem Setup: In Fluent
a) General: Pressure Based Solver, steady,
Model:
• Energy – ON
• Viscous-k-epsilon(Realizable)
b) Boundary Conditions:
• Giving an Inlet Velocity of 5m/sec at the inlet, and 300K air.
• Pressure Outlet is on by default.
• Heated Plate: Giving constant temperature of 723K
• Heat Generation Rate: 1000
• Heat transfer Coefficient: 210
• Mesh Interfaces: We defined interface connecting the interface domain and interface fins and we connected it by coupled wall.

ii. a) Solution Method:
Pressure Velocity Coupling: SIMPLE
b) Solution Initialization:
Solution Initialization: Standard Initialization(Compute From Inlet)

iii. c) Run Calculation:
No of iterations: 250

Results:
When we plot the contours, then we are getting pretty good contours as per our intuition of physical conditions but when we see the numerical values we are observing the air to leave at the same temp it enters.

MOREOVER WE HAVE USED THE SAME SETUP PROCEDURES, OF A WORK PREVIOUSLY DONE USING GAMBIT AND FLUENT 6.3, AND IN THAT WORK NO HEAT GENERATION RATE WAS GIVEN, STILL IT GAVE CORRECT RESULTS BUT IN OUR CASE WHEN WE DON’T GIVE THE HEAT GENERATION RATE (EVEN IF CHOOSE THE CONSTANT TEMPERATURE OPTION), THE PLATE COOLS DOWN.

So can anyone suggest the correct problem setup for the current case of heat transfer from a heated plate using fins.

I am attaching my problem case files, i.e. the ANSYS workbench files, using the same setup conditions, so anyone can check it out and tell the correct method.

https://www.dropbox.com/s/1csudpwioz...%20Problem.rar

OR CAN YOU SUGGEST ANY LINKS FOR SOME TUTORIAL OR VIDEOS, FOR THE CASE OF SIMPLE HEAT TRANSFER FROM A HEATED PLATE WITH FINS, SO THAT WE CAN LEARN HOW TO SET UP A HEAT TRANSFER PROBLEM FOR THE CASE OF FINS FIXED ON A HEATED PLATE.