An axisymmetric two-dimensional mathematical model of the cylindrical evaporator's wick of loop heat pipes is developed to simulate heat transfer with flow and evaporation in the capillary porous structure. Effect of the interaction between the flow field and the liquid-vapor interface on the position of the interface and the curvature of menisci is adequately considered in this model. The flow fields of transient and steady states are obtained at low or moderate heat fluxes. The dynamic and thermodynamic behavior is discussed in this paper. The auto-driving mechanism of "inverted meniscus type" evaporators is validated. Effect of heat flux is investigated in detail. (c) 2006 Elsevier Ltd. All rights reserved.