Physics Setup

Launch Fluent

To launch FLUENT, first double click Setup under Project Schematic.

Check the option "Double Precision". This will make the simulation more accurate, since Fluent will use twice more bits in the calculations.

You can leave the rest as Default. Now press OK to launch FLUENT.

The FLUENT window layout is basically divided into 4 zones:

1) The left most column contain all the possible operations that one may want to perform to setup a simulation, like setting the boundary conditions, selecting the fluid used, and which simplifications to make.

We usually go from the first "General", one by one, until "Run Calculation". However in this tutorial we will have to break a little bit this symmetry to specify what is called "Interface Zones" (not (yet) shown in the list of options).

Here are just the main options; the actual "knob tweak" is made right next to it. Note that once you click in one item from the menu, a grey column appear right next to it showing more detailed options.

2) Sub-options for each main option selected from the left most column. Here we actually modify the way Fluent will behave.

3) The graphical window, showing at first launch the mesh. You can navigate on that using the left mouse button to Pan the mesh.

Drawing a box using the middle mouse button from left to right (either top or bottom) will zoom in, while drawing a box from right to left will zoom out.

The right mouse button will not often be used for our relative simple simulations. It displays the "surface group" the "id" and the "name" of the surface containing the point you clicked.

4) A mesh box where Fluent will print its operations, messages, warnings, iterations, results (as requested), etc.

Enough of talking! Let's start the CFD Simulation!

Check Mesh

It is always a good practice to check mesh, specially if you are importing mesh that wasn't created by you. It is not frequent to get matching errors, particularly when meshes with multiple Cell-Zones like our case.

In order to do that, you can click on Mesh > Check under the upper tab with options, next to File.

You can also note that, when Fluent is first launched, the second menu box (described previously) contains the options for "General". There, on the first option you can see under "Mesh", the option for Check. You can see this highlighted in the above figure.

Lastly, you can type "mesh/check" and hit Enter in the messages box (number 4 from previous description).

Create mesh interfaces

As briefly discussed, we need to start by creating the interfaces between the different zones of mesh.

To account for the rotation of the mesh, we couldn't simply have created one single mesh. Instead, we have to create sub regions, or Zones of meshing.

FIVE ZONES, FIGURE

The mesh created is "non-conformal", i.e. the nodes does not match across the interface), so we need to tell Fluent that the adjacent cell across that interface share information.

ADD MATCH CONTROL TO MESH? (see wind blade tutorial) 
Import mesh as a wbpz file instead o msh? 

(v) Mesh info > size to check number o elements

(v) It's always a good practice to check the mesh. Mesh > check and verify that there are no errors

 (skipped) Display mesh color by ID

before digging into the rest, we need to creat the mesh interfaces for the problem. The geometry is composed of 5 zones:
outer inner and inside blade zones. FIGURE showing this. The mesh created is "non-conformal" (i.e. the nodes does not match across the interface), so we need to tell Fluent that the ajudascent cells across that interface share information.

In order to do that, go under boundary conditions. set xxxx to interface. Note that "mesh interfaces" appeared under the setup menu. Click on that.

...

To explain a little bit about the MFR method, see Numerical Results part, where I wrote something very short.

General: leave p-based

Units: set to rpm

Models:viscous k-eps turb. Realizable

materials leave default. check density of xxx and visc of...

Cell zone conditions:

name zones, centroid, angular velocity. do for top blade

make table with values for other blades

Boundary Conditions:

-farfield 1: velocity inlet....

-farfield 2: pressure outlet...

etc

Go to Step 5: Numerical Solution

Go to all (ANSYS or FLUENT) Learning Modules