• Go to Design → Import/Edit STL File and open the model.
• Align the geometry with the wind direction in the import editor.
• If the model is in English units, adjust the scale factor so the dimensions are correct.
• Delete the default surface in Stallion 3D (Edit → Surface → Delete).

Example model: “Twin Tail” (~77,000 facets).

• Set Angle of Attack (example: 2°).
• Define the Reference Area and Reference Length for coefficient calculations (example: 27.2 m² and 2.3 m).
• Set the Center of Gravity location as needed (example: x ≈ 5.72).

Reference values enable comparison against published data and consistent nondimensional coefficients.

• Open CFD Solver → Setup.
• Choose a cell count (example: ~0.96M cells) and turbulence model (RANS).
• Set a cubic computational domain using minimum x,y,z and side length.
• Use radiation boundary conditions for far-field boundaries.
• Specify total iterations (example: 35,000) and the restart/save cadence (e.g., every 1,000 iters).
• Launch “Generate Grid & Solve.”

• Go to Flow Field → Actuated Disks.
• Add a disk: set force, center of rotation, rotation direction, inner & outer radii, and name.
• Add a second disk (example: ~2000 N each, left/right positions).

Use paired disks to represent counter-rotating propellers and capture propwash.

Under Aerodynamic Data → Coefficients, example results for AoA = 2° and V ≈ 1000 m/s (per the raw transcript):

• Cl ≈ 0.252
• Cd (pressure) ≈ 0.0119; Cd (skin friction) ≈ 0.0125; Total Cd implied
• L/D ≈ 10.34
• Cm about CG ≈ −0.0158

Forces (example): L ≈ 9000 lbf, D ≈ 912 lbf (also available in SI units).

Actuator disks power (example): left and right each ≈ 189.5 kW, total ≈ 379 kW.

Note: Stallion 3D does not assume propeller/engine efficiency; multiply by a factor (e.g., 1.2–1.3) for realistic shaft power.

• View surface pressure coefficient and velocity contours.
• Add streamlines to visualize flow structures and propwash.
• Slice the flow field to inspect internal regions; display grid cross-sections.
• Plot Cp along the wing at y = 4 to study lift distribution.

In the example, the solver generated ~800k cells and converged in roughly 14k iterations.

On a laptop, the run completed in < 14 hours (per the transcript example).

Note, the latest version of Stallion 3D is now 4 times as fast