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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