  Large parameter studies of fluid dynamic instabilities can crucially be
simplified, if the user does not need to specify the simulation time. For this
purpose, a steady state detection is implemented in the CFD library OpenFOAM.
It terminates simulations automatically if characteristic measurements do not
change over time, i.e. when saturation is reached. For that purpose, recent
data is compared to previous one using two selectable methods. Both calculate a
value used as steady state indicator. The first method performing a two sample
Student's t-test examines the difference between the means. Similarly, the
second method utilises a two sample f-test checking for changes between the
variances. Both methods are briefly described, compared and their specific area
of application is discussed. Their usefulness is demonstrated with a simple
exemplary test case.
