ABSTRACT

A study of directional solidification of a weak binary alloy (specifically, Bi-1 at%Sn) using a fixed grid single domain approach has been undertaken. The enthalpy method is used to solve for the temperature field over the computational domain including both the solid and liquid phases. Latent heat evolution is treated as a source term in the energy equation. A source term accounting for the release of solute into the liquid during solidification has been incorporated into the solute transport equation. The vorticity-stream function formulation is used to describe thermo-solutal convection in the liquid region. In this paper we present a numerical simulation of g-jitter: the small, rapid fluctuations in gravitational acceleration which may be experienced in an orbiting space vehicle with a background gravity of 1 μg. Results showing the effects of the periodic disturbances for a range of amplitudes, frequencies (multi-component) and actual acceleration data obtained during a space flight, on the solute field and segregation are presented.