Test object — Choose Sphere for a bluff-body baseline, or switch to STL and drag-and-drop any binary or ASCII STL file. The mesh is cross-sectioned and rasterised into the solver automatically.

Conditions — Use the sliders or type directly into the number boxes. Air speed (1–515 m/s), Object size (20–600 mm), and Angle of attack (−90° to +90°) all update the flow field in real time.

Overlays — Toggle Streamlines, Pressure, Forces, Boundary layer, Labels, and Grid using the buttons above the tunnel view. Streamlines are colour-coded by local flow speed (blue = slow, red = fast).

Graphs — Switch between Cp (pressure coefficient around the surface), Forces (drag, lift, dynamic pressure), Profile (silhouette preview), and Polar (Cl vs Cd sweep, STL only).

Refresh flow — Resets the fluid solver to a clean freestream without changing your settings or unloading your STL. Useful if the wake looks odd after a large parameter change.

Undo / Redo — Steps back or forward through your speed, size, AoA, and object changes. Up to 30 steps of history.

Units — Toggle between SI (m/s, N, Pa) and Imperial (mph, lbf, psi) at any time; all readouts and exports update immediately.

Exports — PNG saves the current tunnel view; CSV exports a full 1–515 m/s sweep of coefficients and forces; PDF Report bundles the stats and all four graphs into a printable A4 document.

Keyboard shortcuts — Space pause/play  ·  R reset  ·  1–4 switch graph tabs  ·  Ctrl/⌘ Z undo  ·  Ctrl/⌘ Shift Z redo  ·  Right-click tunnel or graph for a context menu.