Wrong initialization of stepFraction_ in particle.C

Summary

Location: https://develop.openfoam.com/Development/openfoam/-/blob/develop/src/lagrangian/basic/particle/particle.C#L530 and lines 551, 584 as well.

In v2012, in the particle.C code, a variable called stepFraction_ is initialized to be 1, while in all previous versions (v2006 or earlier) it was initialized to be 0. The definition of stepFraction is not changed, therefore, I believe the correct initialization is 0.

Environment information

• OpenFOAM version : v2012

Possible fixes

Change lines 530 (https://develop.openfoam.com/Development/openfoam/-/blob/develop/src/lagrangian/basic/particle/particle.C#L530), 551, 584 to: stepFraction_(0.0),. This is how it was in OpenFOAM v2006 and previous versions.