Formation of spiral waves in cylindrical containers under orbital excitation

The lowest swirling wave mode arising in upright circular cylinders as a response to orbital excitation has been widely studied the last decade, largely due its high practical relevance for orbitally shaken bioreactors. Our recent theoretical study (Horstmann et al. , J. Fluid Mech. vol. 891, 2020, A22) revealed damping-induced symmetry breaking mechanism that can cause spiral structures manifested so far disregarded higher rotating modes. Building on this work, we develop linear criterion describing degree of spiralisation and classify different regimes function most relevant dimensionless groups. analysis suggests Bond numbers shallow liquid layers favour formation coherent waves. This result paved way find predicted our interfacial sloshing experiment. We present two sets experiments, with characteristic damping rates, verifying both overdamped waves conformity predictions.