On the convective disturbances induced by g-jitter on the space station

A numerical tool has been prepared to quickly predict the overall disturban ces for the typical Microgravity Environment (MGE) on the ISS. A reference study case (that shows a large sensitivity to acceleration disturbances) is identified and numerical simulations are carried out to compare the result s of the solution of the full Navier-Stokes equations with a time-dependent acceleration (that give the instantaneous time-dependent flow) with the so lutions of the time-averaged field equations (Gershuni formulation), contai ning all the g-jitter terms (like those that identify the microgravity envi ronment of the ISS) grouped in a single parameter. The paper shows that the overall disturbances of the thermo-fluid-dynamic field are easily evaluate d assigning as input to the fluid-dynamic code a single (equivalent) freque ncy g-jitter (in the direct formulation) or an overall vibrational Rayleigh number (in the time-averaged formulation). The code is validated and appli ed to the problem of thermodiffusion in a typical metal alloy. (C) 2001 Int ernational Astronautical Federation. Published by Elsevier Science Ltd.