Gallery

Fluids, everywhere

Flows computed with Conatus, drawn like the photographs of An Album of Fluid Motion: magnitudes in smoke greys, signed fields through black at zero, from red to glass green. Open a plate to see it at full size.

In motion

Two Conatus runs, frame by frame, looping.

Kelvin–Helmholtz billowsPassive dye between two shear layers rolling up, Re = 400, t = 2 to 9.95. 384 × 192 Fourier modes, RK443, dt = 0.0025, CPU. The last frames cross-fade into the first where the film loops: a display transition, not part of the run.
Rayleigh–Taylor instabilityHeavy fluid falling into light fluid, Ra 1e7, computed with Conatus. The film fades through black where it loops: a display transition, not part of the run.

Two horizontal shear layers rolled up into rows of spiral vortices on a black background: the upper row in red (negative vorticity), the lower row in green (positive vorticity), thin filaments wrapping around each core.

Shear flows · cartesian

Kelvin–Helmholtz billows

Two horizontal shear layers rolled up into rows of spiral vortices on a black background.

A pale horizontal band of passive dye between two shear layers, its edges curled into rows of spirals that entrain dark fluid, outlined by one thin fluorescent yellow-green line at half concentration.

Shear flows · cartesian

Kelvin–Helmholtz dye

A pale horizontal band of passive dye between two shear layers, its edges curled into rows of spirals that entrain dark fluid, outlined by one thin fluorescent yellow-green line at half concentration.

A long horizontal slab of convecting fluid on black: bright hot plumes rise from the bottom wall and dark cold plumes sink from the top, carried by large convection rolls across a nearly uniform grey interior.

Convection · cartesian

Rayleigh–Bénard convection

A long horizontal slab of convecting fluid on black.

Space-time diagram of a chaotic Kuramoto–Sivashinsky solution: time runs left to right, space vertically; wavy red and green stripes of negative and positive u merge, split and drift, separated by black zero lines.

Dynamics · cartesian

Kuramoto–Sivashinsky chaos

Space-time diagram of a chaotic Kuramoto–Sivashinsky solution.

A horizontal band of alternating red and green vertical stripes fading to black at the top and bottom walls: the azimuthal velocity of Taylor vortices between two cylinders, with thin silver closed streamlines circling the dark vortex centres.

Rotating flows · cylinder

Taylor–Couette: the first Taylor vortices

A horizontal band of alternating red and green vertical stripes fading to black at the top and bottom walls.

A dense labyrinth of light and dark parallel stripes of fixed width, curving in patches of different orientations that meet at defects and grain boundaries.

Patterns · cartesian

Swift–Hohenberg labyrinth

A dense labyrinth of light and dark parallel stripes of fixed width, curving in patches of different orientations that meet at defects and grain boundaries.

A globe seen from mid-northern latitudes on a black background, covered by large alternating green and red vorticity lobes: four around each hemisphere, the northern and southern lobes of opposite sign across the equator, with faint concentric ripples near the pole.

Rotating flows · sphere

Rossby–Haurwitz wave on the sphere

A globe seen from mid-northern latitudes on a black background, covered by large alternating green and red vorticity lobes.

A wide band of red and green lobes on black: the streamwise velocity of the least stable wave of plane channel flow, strongest in bright layers just inside the top and bottom walls, the upper and lower halves of opposite sign, with a sharp phase kink near each wall.

Shear flows · cartesian

Tollmien–Schlichting wave in a channel

A wide band of red and green lobes on black.