Linear and Pendular Acceleration Effects in Fluid Dynamic Experiments Under Low Gravity

摘要

To study the influence of residual acceleration on fluid physics experiments in microgravity environments, the different driving forces in the vorticity equation (leading to convective motion in a fluid cell) are considered. Steady and linear time-dependent accelerations generate convection in an otherwise quiescent fluid only in the presence of density gradients. Pendular acceleration may induce convective motion even in the absence of a density gradient induced by temperature and/or species concentration differences. Numerical simulations are carried out for different study cases, in the presence of low-frequency and high-frequency oscillations, based on realistic values of the accelerations onboard space platforms. The numerical results are compared with experimental results, obtained in microgravity and ground laboratories.