Flupaint: simulating electrostatic paint spraying
A simulator developed by VSOLUTION on OpenFOAM that predicts the paint thickness deposited by an electrostatic sprayer: booth aerodynamics, electric field, charged droplet trajectories and multi-pass sweeps, down to the thickness map on the part.
The challenge
Tuning an electrostatic paint process in a booth is expensive: every trial stops the line, and the actually deposited thickness is only discovered afterwards. Overlap over-thickness between passes and transfer efficiency are hard to anticipate. The goal: predict thickness by simulation, for any sprayer and any part.
Three coupled physics
VSOLUTION developed Flupaint, a simulator built on OpenFOAM that couples the three phenomena governing the deposit:
- The turbulent air flow (k-ω SST), fully configurable: bell rotation, air and paint injections
- The electric field between the sprayer and the part, solved by a purpose-built solver
- The paint droplets, charged at the Rayleigh limit and tracked as Lagrangian particles under the combined action of air flow and electrostatic force
From impact to thickness map
At each impact, the deposit is accumulated facet by facet on the part mesh, with smoothing and spreading options, then displayed directly on the 3D model. Full sprayer sweeps are simulated automatically thanks to an interpolation process that makes multi-pass cycles fast and repeatable to compute.
Results
- Micron-level thickness maps on full parts, localized overlap over-thickness identified before any booth trial
- Any sprayer and part model can be imported, with fully configurable particle physics (density, diameter, charge, surface tension)
- A 100% open-source chain: OpenFOAM plus in-house solvers, no per-use license