Interactive simulation
Flow inside a packed bed
Move the controls and watch what happens to the fluid. Every state of the bed is solved beforehand: the pressure field comes from ∇·(k∇p) = 0 on a 640×384 grid, and the tracer is advected over that field in your browser, live.
Thickens every grain. It squeezes the throats and, past a point, cuts the path off.
Three different beds, from the loosest to the densest. The geometry changes, the fluid does not.
The field does not change with flow rate: the problem is linear. What changes is how much diffusion manages to even out.
- Porosity
- —
- Permeability
- —of the initial
- Peak velocity
- —the mean
- Tanks in series
- —from the RTD
Residence time distribution
Built live from the particles as they leave.
What it is and what it is not. It is a real numerical solution, not an illustration: finite volumes, harmonic face averages and a conservative velocity field. But it solves Darcy flow in a heterogeneous permeability medium, not pore-scale Stokes: there is slip at the grain surface and no viscous shear inside the pore. It reproduces channelling, dead zones and the shape of the RTD well; it does not replace a proper CFD solution. It is a 2D bed, so the porosities are not comparable with those of a sphere packing.