An experimental study carried out aboard the Mit station showed that a stea
rin candle can burn for a long time even inside a closed volume without a f
orced circulation. Such experiments imply that there is some mechanism for
a permanent transport of the oxidizer to the flame zone. It can be assumed
that a jet of combustion products outflowing along a normal direction with
respect to the flame surface produces a vortex motion in the environmental
space, which delivers oxygen to the flame zone. To verify the feasibility o
f combustion to be sustained by such a mechanism, a mathematical statement
of the problem of combustion inside a closed region under zero gravity with
out a forced circulation was formulated. A simplified model was put forward
to simulate the combustion of solid and liquid substances, which allowed t
he effects of chemical reactions to be reduced to boundary conditions. The
computations showed that the proposed mechanism of oxygen transport to the
flame zone really can sustain an almost stationary regime of combustion.