Sloshing reduction in microgravity with passive baffles: Design, performance, and supplemental thermocapillary control

A detailed analysis of the design and performance of passive baffles for sloshing reduction in microgravity is presented. Sloshing dynamics are investigated for a rectangular container holding a LxH=30 x 15 mm(2) volume of liquid with properties similar to a 5 cSt silicone oil. The system response to a pulse-like perturbation is analyzed in terms of the sloshing frequency omega, decay time tau d, and damping ratio xi = gamma/root gamma(2)+omega(2), characterizing the decay rate gamma proportional to tau (-1)(d) relative to omega. We explore first simple rectangular baffles, parameterized in terms of their length and height, orientation, and position of their center, finding that the vertical centered baffle is optimal for its good performance and simplicity. The analysis is further extended to other designs of higher complexity, including multiple-baffle arrangements, cross-shaped baffles, and free surface baffles. Finally, motivated by the recent work of Peromingo et al. ["Sloshing reduction in microgravity: thermocapillary-based control and passive baffles," Phys. Fluids 35, 102114 (2023)], we also demonstrate the effectiveness of passive baffles combined with active thermocapillary control. As a whole, the present results suggest a maximum achievable sloshing reduction of approximately 90%.