AbstractThis paper describes a series of numerical experiments designed to explore the close interplay between the rotational, the pressure gradient, and the buoyancy, force fields in concentrated vortex flows driven thermally by heating from below. The calculations are motivated by a desire to understand the dynamics of dust‐devils and to provide a theoretical framework in terms of which both past and future observations of these vortices may be interpreted.In the model, a vortex is generated along the vertical axis of a cylindrical region of fluid bounded by a rigid (no‐slip) lower boundary, and a sidewall consisting of a rigid, impermeable upper portion and a rotating, porous, lower portion through which fluid at ambient temperature enters the cylinder and acquires rotation. The flow is driven by maintaining a circular portion of the lower boundary at a fixed temperature above ambient and fluid is allowed to enter or leave the cylinder normally through the upper boundary. For a cylinder of given size, the flow behaviour depends on the magnitudes of two nondimensional parameters which characterize the strength of the thermal forcing and of the imposed rotation. According to the sizes of these, flows with axial downflow on part or all of the axis of rotation are possible and, in some cases, a closed cell of reversed flow is possible. In each case it is possible to give a complete description of the force field balance which combines to produce the particular flow pattern.The calculations go a long way to providing an understanding of the main features of dust‐devils as observed in a careful and detailed study by Sinclair and corroborate well with the experimental results of Fitzgarrald in relation to laboratory vortices. In particular, we show how rotationally induced axial pressure gradients can supplement buoyancy forces in accelerating the vertical flow in dust‐devils as appears necessary to explain the large vertical accelerations observed near the ground in these vortices.