FLUID In the literature: open

Scaling of the splash-threshold gas pressure with viscosity and gas

In plain words

The air pressure below which splashing stops depends on the liquid and the gas. A single rule that covers thin and thick liquids and different gases has not been found.

Precise statement

Measure and predict $P_T$ as a function of liquid viscosity (about 0.3 to 10 cP), V, R and gas molecular weight, establishing whether the gas enters only through its density, through its mean free path (rarefaction in the thin gas film), or both, and whether one scaling law covers low- and high-viscosity liquids.

What would settle it

Threshold maps over viscosity, speed and gas species collapsed by a single derived scaling variable.

Status in the literature

Threshold scalings measured for low-viscosity liquids (arXiv:1403.3145) are not reproduced by one theory across viscosities.