**Temperature distribution in a Cylinder**

We wish to compute the temperature distribution in a long steel cylinder with inner radius 5 inches and outer radius 10 inches. The interior of the cylinder is kept at 75 deg F, and heat is lost on the exterior by convection to a fluid whose temperature is 40 deg F. The convection coefficient is 0.56 BTU/hr-sq.in-F and the thermal conductivity for steel is 0.69 BTU/hr-in-F.

**1.** Start ANSYS and assign a job name to the project. **Run
Interactive -> set working directory and jobname.**

**2. Preferences -> Thermal will show -> OK**

**3. **Recognize symmetry of the problem, and a quadrant of a
section through the cylinder is created using ANSYS area creation tools. **Preprocessor
-> Modeling -> Create -> Areas -> Circle -> Partial annulus**

The following geometry is created.

**4. Preprocessor -> Element Type -> Add/Edit/Delete -> Add ->
Thermal Solid -> Solid 8 node 77 -> OK -> Close**

**5. Preprocessor -> Material Props -> Isotropic -> Material
Number 1 -> OK**

** EX = 3.E7 **(psi)

** DENS =
7.36E-4 **(lb sec^2/in^4)

** ALPHAX =
6.5E-6**

** PRXY = 0.3**

** KXX = 0.69 **(BTU/hr-in-F)

**6. **Mesh the area and refine using methods discussed in previous
examples.

**7. Preprocessor -> Loads -> Apply -> Temperatures -> Nodes
**

Select the nodes on the interior and set the temperature to 75.

**8. Preprocessor -> Loads -> Apply -> Convection ->
Lines**

Select the lines defining the outer surface and set the convection coefficient to 0.56 and the fluid temp to 40.

**9.** **Preprocessor -> Loads -> Apply -> Heat Flux
-> Lines**

To account for symmetry, select the vertical and horizontal lines of symmetry and set the heat flux to zero.

**10. Solution -> Solve current LS**

**11. General Postprocessor -> Plot Results -> Nodal Solution ->
Temperatures**

The temperature on the interior is 75 F and on the outside wall it is found to be 45. These results can be checked using results from heat transfer theory.