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To probe: Click on "Probe" icon. Then change the variable to "Velocity" and click on the screen where you wanna probe.

Tip speed ratio (TSR)

To calculate the TSR we first need to extract the velocity from CFD-Post. Since our reference is the value of velocity at r=0.04m, we need to find some way to extract the velocity of the blade at that particular location.

One can plot the velocity vectors and read off the legend. However this is quite imprecise.

One of the ways to do this trick is to plot the velocity distribution along the X coordinate for the whole surface of the right blade, and then extract the value at x=0.04m. Since the "wall" entity is a closed line, the plot should also be circular. As the blade is rectangular, we should expect abrupt change in velocity very close to the maximum and minimum X. Let's do it!

First thing to do is to create a Polyline over the wall of the right blade. Select Location > Polyline. 

FIGURE 9

Name it "wall right" and for "Method" select "Boundary Intersection". For "Boundary List" select "blade_right symmetry 1" and for "Intersection With", select "wall_blade_right". Click Apply.

FIGURE 10

Next, insert a chart (Insert > Chart). Name it "Veloc at blade". Under "Data Series" tab, change the Location to the created "wall right".

Under "X Axis" tab, change the Variable to "X".

Under "Y Axis" tab, change the Variable to "Velocity in Stn Frame v". This is the velocity in the Stationary frame of reference (our interest). We are taking only the y component because we know that the velocity of the blade should be only in the y direction at that location. Click Apply.

The chart should look like this. The point of interested is marked by the dashed lines. Also notice that at the edges of the plot there is an abrupt change in velocity, as expected. The "closed loop" plot expect is in fact happening, but the curve collapsed into a single line. You can she the curves separated if you choose "Velocity in Stn Frame" as Y Variable instead

FIGURE 11

note it's circular so there should be two plots superimposed.

Recall from pre-analysis that we calculated the expected value 

Check mass flow

Velocity contours

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Pressure contours

Torque

Vorticity?

Cp=Cm (from fluent) * TSR

When extracting the Torque, explain that the Moving Frame of Reference is used to calculate (FOR FEA) omega squared times the radius times the mas of each element to compute the force exerted by the fluid on the blades. (check Wind Blade 2 tutorial, under Physics Setup, second video, around 3:30. It is for FEA, we should get the analogy to fluid before).

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