sphereDrag does not work with very small particle size

Summary

sphereDrag does not work with very small particle size (e.g. 1e-5).

Steps to reproduce

Within the provided case (pitzDaily), run pisoFoam to obtain the simulated fields and then run icoUncoupledKinematicParcelFoam.

Example case

pitzDaily_bug.tar.gz

What is the current bug behaviour?

Using icoUncoupledKinematicParcelFoam, strangely freeze particles are observed after a short period of time (below images) when setting fixedValueDistribution with particle size of 1e-5 with sphereDrag and gravity. If you turn off the sphereDrag, it will works normally.

What is the expected correct behavior?

The particles should escape at the outlet.

Relevant logs and/or images

Environment information

• OpenFOAM version : v2406|v2312|v2206
• Operating system : ubuntu
• Hardware info :
• Compiler : gcc

Possible fixes