TransitionModel ( TransitionModelIndex )

Options Card
Arguments TransitionModelIndex the index of the transition model as they appear in the combo box on the polar card:
1 — Eppler, standard
2 — Eppler, extended
3 — Cebeci-Smith
4 — Michel 1
5 — Michel 2
6 — Granville
7 — Drela en approximation (Xfoil pre 1991)
8 — Drela en approximation (Xfoil post 1991)
8 — Arnal, approximation by Würz
 
Description Switches the transition model used to detect transition from laminar to turbulent state.
Remarks The selected transition model is used for the results of the Flowfield, Velocity, BoundaryLayer and Polar cards.
Performs the same action as a new selection in the "Transition Model" combo box on the Polar card. The transition criteria are described under "Boundary Layer Method"on the JavaFoil main page set.

The roughness factor r is only used in the Eppler models and corresponds to the choices in the roughness combo box. The NACA standard roughness as defined in [34] is a leading edge roughness, but can be simulated by using r=2.
The NACA definition is as follows: carborundum grain of 0.01" size, covering 5-10% of the area from x/c=0% to 8% of the airfoil model having a chord length of 24". Reynolds number were in the range 3 ... 9 x 106.