Modeling of Taconis oscillations in a tube with submerged open end

Abstract

Narrow tubes inserted into cryogenic tanks often experience Taconis oscillations, representing excitation of the tube acoustic modes. These oscillations are caused by large temperature gradients and can lead to significant enhancement of heat leaks into cryogenic systems and boil-off losses. In this study, a thermoacoustic model is employed for a tube with an open end submerged into cryogenic liquid to determine limit-cycle magnitudes and frequencies of Taconis oscillations. The nonlinear minor loss associated with fluid motion at the open tube end serves as the amplitude-saturation mechanism. The model has been calibrated against tests data and applied for a parametric study with variable tube position in helium and hydrogen systems, including a case with a long tube at high mean pressure in a storage tank for liquid hydrogen fuel.