Wind Tunnel Boundary Layer Lab: Flat-Plate Growth & Separation (2D)

This 2D companion models the same flat-plate boundary layer as the 3D version, drawn as a plain side-on canvas built for reading the physics rather than orbiting a scene: a shaded region traces the boundary layer as it grows downstream along a √x curve, a bank of streakline particles gets visibly retarded and deflected as it passes through that layer, and switching to the Profile view freezes four velocity-profile stations so you can compare how the near-wall shape flattens with speed, roughens with surface texture, and — past a high enough adverse pressure gradient — reverses into a separation bubble. Live readouts convert the same freestream speed, plate length and roughness controls into a Reynolds number, a Blasius-style layer thickness and a wall-shear estimate, so the visual growth of the layer stays tied to the numbers driving it.