A new strategy for constructing microgravity culture environment via gas-liquid coupled oscillatory flow field

The mainstream Rotating Cell Culture System (RCCS) simulates microgravity via three-dimensional dynamic rotation, which differs from true space microgravity in physical mechanisms. In this context, the present investigation innovatively proposes a new microgravity simulation strategy based on Einstein’s equivalence principle—establish a stable and controllable quasi-free-fall flow field environment by constructing a gas-liquid coupled oscillatory system inside the U-tube. Based on the analysis of the physical modeling of the oscillating flow field in the vertical U-tube and the CFD-VOF gas-liquid coupling simulation experiments with parameters ( D = 15 mm, R/D = 1.3) shown that in each oscillation period, 71% of the liquid will lose weight in two vertical sections, and when the liquid at the maximum volume ratio the average weight loss peak value is 0.02 g , achieving spatial low microgravity (10 −2 g ), and the dynamic characteristics of the pressure and shear stress of the flow field meet the mechanical boundary conditions of cell culture. This approach is expected to establish a new paradigm for ground-based simulation of microgravity effects in space, offering novel technical/theoretical support.