A numerical analysis of the evaporation process in a flat plate heat pipe (FPHP) is presented. Three different heat flux configurations were applied at the evaporator section: parabolic, linear and constant; and three different wick thicknesses were evaluated. A two-dimensional explicit Finite Difference Model was used to conduct the transient computational analysis of the heat pipe. The results indicate that the vaporization rate was more intense at the evaporator for the parabolic heat flux distribution, than for either the linear or constant heat flux distributions. The velocity field is nearly identical to the shape of the input heat flux distribution. The maximum Mach number for all the cases analyzed was low, indicating that the incompressible flow assumption in the vapor was valid. The modeling results also indicated that the thickness of the heat pipe wick was a significant factor in the determination of the overall thermal resistance, with the resulting temperature drop proportional to the thickness of the wick. Typical distributions of the field variables, particularly the temperature in the wall, and the temperature, velocity and pressure in the wick and the vapor core of the flat plate heat pipe are also presented and discussed.

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