The phenomenon of thermal creep, according to which a rarefied gas wil
l ''slip'' at a fluid/solid interface in the presence of appreciable t
emperature gradients along the interface, has been previously treated
by analytical techniques in the one-dimensional, semi-infinite, linear
ized case. The more general problem of multidimensional gas flows at h
igh Delta T/T values typically defies analytical or semi-analytical so
lution. We employ a direct simulation Monte Carlo method to a hard-sph
ere gas in order to study the characteristics of thermal creep convect
ive motion in a Cartesian, two-dimensional, confined flow geometry whi
ch captures important features of ampoules used in microgravity experi
ments on crystal growth. Vortex roll formation is indeed observed in t
hese numerical experiments even for zero-gravity conditions, driven by
thermal creep at the non-isothermal boundaries and in close resemblan
ce to the classical fluid dynamic problem of the wall-driven cavity. (
C) 1995 American Institute of Physics.