Faraday waves and period tripling in a horizontal circular tank

Understanding wave kinematics is crucial for analysing the thermodynamic effects of
sloshing, which can lead to pressure drops in non-isothermal cryogenic fuel tanks. In
the research reported here, Faraday waves in a horizontal circular tank (partially filled
with water) under vertical excitation are investigated. The tank geometry is referred to
as a horizontal circular tank throughout, with its circular face oriented perpendicular
to the horizontal plane. Firstly, this paper addresses the eigenvalue problem through
linear potential flow theory, in order to provide theoretical evidence of Faraday waves
in horizontal circular tanks, the impact the density ratio has on the eigenvalues is then
considered. Secondly, an experimental investigation testing multiple liquid fill levels is
conducted. A soft-spring nonlinear response is demonstrated throughout the parameter
space. The results showed larger sloshing amplitudes for low fill levels and smaller
sloshing amplitudes for high fill levels. Asymmetry between anti-nodes at the container
sidewalls and through the tank centreline are evident for low fill levels. Moreover, the
sloshing wave amplitude at which breaking waves occur is smaller for high fill level
conditions. Finally, period tripling was observed for all fill levels tested, confirming
nonlinear mode interactions before the onset to wave breaking.