Experimental Methodological Investigations of Sloshing-Induced Mass Transfer Coefficients for Aircraft Tanks

This paper aims to provide experimental methodologies for estimating the characteristics of mass transfer, namely, the Nusselt number, induced by vertical sloshing in horizontal cylindrical tanks pressurized with two-phase fluid by replicating operating conditions that would occur in tanks containing liquid hydrogen for future generation aircraft. A tank with a circular cross section, scaling a slice of an aircraft tank, is used as a test bed, and water is used as a surrogate fluid for replacing the liquid hydrogen. The paper first provides the estimation of the Nusselt number for random imposed motion and shows that, in the case of stationary processes, the Nusselt number results constant on average in time and is independent of the fluid thermodynamic state. As a consequence, the Nusselt can also be mapped for deterministic harmonic processes with variable amplitude and frequency.