Sign-up for free online course on ANSYS simulations!...
Highlight "Reports" in the left box. Then select "Fluxes" and click "Set Up...".
FIGURE 1
Note that "Mass flow rate" is already selected.
...
First, the external boundaries. In the "Flux Reports" window, locate and highlight "farfield1" and "farfield2" and hit "Compute". The mass flow rate though that boundary is now printed in the command window.
FIGURE 2
Note that 73.5kg/s get into out domain and virtually everything leaves. The imbalance is 7.4e-9kg/s which is negligible considering the total amount of flux in the system. Nice!
...
Proceed similarly as before and check the mass flow through the hub_inner boundary. You could also select hub_outer and the result would be almost identical.
FIGURE 3
Remember to deselect farfield1 and farfield2 before hitting compute!
You should get an imbalance of 3.42e-10kg/s which is essentially zero. Cool!
Velocity Contours
To plot the velocity contours we will use CFD-Post. You can now close FLUENT.
In Workbench, under Project Schematic, double click Results. This will launch CFD-Post
FIGURE 4
CFD-Post usually opens with an isometric view of the part. Since we're in a 2D analysis, this is not very useful for us. So, the first thing to do is click on the Z axis arrow (bottom-right corner of graphics window) to change the view.
Now insert a Contour. Click on the Contour icon (or Insert > Contour)
FIGURE 5
Name it "Velocity contour". A new box will appear on the left side of the screen. Summary of what to do:
...
Locations: click on the three dots "..." on the side. select all names with "symmetry 1" in it. Hold the Ctrl key for that. You will select 5 zones in total, see figure.
FIGURE 6
Variable: change is to "Velocity".
...
You can zoom into the bug, drawing a box with the right mouse button.
FIGURE 7
Note that it's very clear the effect of when the blade is perpendicular to the flow: a huge recirculation bubble is made. This will negatively affect other turbines placed downstream of this one. This is a very important thing to consider when designing an array of VAWTs.
...
To probe: Click on "Probe" icon. Then change the variable to "Velocity" and click on the screen where you wanna probe.
FIGURE 8
Check mass flow
Velocity contours
...