NUMERICAL STUDY ON GAS-LIQUID INTERFACE WAVES IN PARTIALLY FILLED TANKS UNDER MICROGRAVITY CONDITION

The characteristics of liquid-gas interface movement, as well as the distribution and motion of the liquid and gas phases, under the interference of residual gravity or acceleration in partially filled tanks in microgravity are the key fundamental for advanced space fluid management technology. According to the general configuration and size of space propellant tanks, three scale-down models are designed based on the similarity criterion of the Bond number. The gas-liquid two-phase flow and the wave propagation along the interface caused by changes in gravity in the prototype tank and scale-down models are numerically simulated. The numerical simulations verify the flow similarity among the prototype tank and the scale-down models. It is found that on the premise of satisfying the similarity criterion of the Bond number, the systems also approximately satisfy the similarity criterion of the Weber number, or equivalently, approximately satisfy the similarity criterion of the Froude number. In addition, the results also show that there exist slight deviations among the prototype tank and the scale-down models, which may be mainly caused by the difference of viscous dissipation. Based on the similarity criterion of the Weber number, with the increase of scale, the size of tank decreases, the driving forcing by the surface tension after the change of gravity strengthens, the flow velocity increases, and thus the viscous dissipation increases at the same Weber number. The numerical results in this paper confirm the above conclusions. The relevant findings can be helpful for the design of ground simulation tests of the liquid management technology of space propellant tanks.