After concluding the experiments, all the data was analyzed. Below are the gathered results, along with the HPC of the holes from which these conclusions were made:
- Airflow does in fact enter the hole, as predicted. Below is an image which clearly shows the string following the direction of airflow entering the hole in the airfoil.
- A hole with an area of less then 2% of the airfoil, does not allow air to enter easily, because the opening is too small for viscous air (K 5 =0.05, HPC 24 6 51 – 24 6 29).
- A hole which faces forward allows air to enter more freely, therefore increasing the airflow velocity in the hole (K 3 =1.3, HPC 13 20 35 – 13 20 43).
- The best location for the hole openings is at the maximum pressure difference location (HPC 7 15 39 – 7 15 39 and HPC 13 20 35 – 13 20 43).
- A hole with the area of the upper opening of more than 15% of the airfoil area, increases turbulence behind the hole (HPC 33 30 39 – 33 32 38).
- Airflow velocity in the hole does not depend on K 4 . It depends only on the area of the smallest opening of the hole (HPC 13 7 32 – 13 16 39 and HPC 12 19 42 – 12 6 44).
- Highest increase in airflow velocity was observed on holes where B > A (HPC 13 7 32 – 13 16 39).
- End plates effect the airfoil, by eliminating the wing tip verticies effect.
- The ideal angle of attack for the airfoils tested, and at the given testing conditions is about 7°. Any more, and there begins to be turbulence at the maximum pressure difference location. Any less and the pressure difference begins to drop.
