The Critical Rayleigh Number in Low Gravity Crystal Growth from Solution
P. W. G. Poodt,  P. C. M. Christianen, W. J. P. van Enckevort, J. C. Maan, and E. Vlieg
Cryst. Growth Des., 8 (7), 2194–2199, 2008

Abstract:
If crystal growth from solution takes place in a closed container, a critical Rayleigh number can be defined, below which buoyancy driven convection is suppressed and mass transport is completely determined by diffusion at gravitational accelerations higher than 0g. Using finite element simulations and an analytical model, we show that it is possible to predict the critical value of the Rayleigh number. This result can be used to optimize growth conditions for microgravity protein crystal growth, if the gravitational acceleration cannot be canceled completely, like in space, or is canceled inhomogeneously, like in gradient magnetic fields.