Computation vs Experiment

We compare below Navier-Stokes/slip computation with measurements for pressure distribution (C_p curve) and lift and drag coefficients.

1. Pressure Distribution: Measurements by Gregory

Pressure distribution over section of upper an lower surface of NACA0012 measured by Gregory and O’Reilly (click on image for better resolution):

2. Pressure Distribution: Measurements by Ladson and Gregory

From a NACA0012 Airfoil Validation Case we collect

3. Pressure Distribution: Computation

Compare with Navier-Stokes/slip computatiuon for aoa = 10:

with a zoom at the trailing edge:

Notice the pressure oscillation at the trailing edge as a result of 3d rotational slip separation, with a local mean-value around the trailing edge which is close to zero, which is what is recorded in the experiment. The pressure oscillation can be seen as a replacement of the high pressure of potential flow.

We see close agreement over the entire pressure distribution curve.

4. Two Element 30PN30P Wing

Here is another comparison of surface pressure for an airfoil with flap:

We see close agreement over the entire pressure distribution curve.

5. Lift and Drag: Computation vs Measurements by Ladson

Comparison of Navier-Stokes/slip computation with measurements by Ladson shows computational results within variation of measurements with different wing surface roughness:


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