ETD

• microbo
• microgravity
• openfoam
• pulsating heat pipe

The inescapable human desire to move further in space exploration is leading towards higher spacecraft power levels and electronics miniaturization. This trend not only affects power systems but also thermal control ones in terms of higher amount of heat to be dissipated and higher heat fluxes. PHP, a two phase passive device working in the confined flow region, is a promising solution in that it meets all of a future space mission requirements: it is simple, light, cheap, passive and exhibits adequate thermal performance. Recently an hybrid type of PHP (called LTS/PHP) has been proposed for space use only. This pointed out that the effect of gravity on flow confinement inside two phase wickless devices is not fully understood yet. A CFD approach to the problem is a powerful tool to unveil the secrets of this phenomenon. The VOF model developed by prof. A. Georgoulas and implemented in OpenFOAM was adopted. As a first step toward the microgravity validation of his model, the present work deals with the simulation of a recent parabolic flight experiment by dr. G. Zummo (ENEA). Considering a quasi-2D axysimmetric geometry of the 4 mm ID test section, the setup for the validation of the code is tested for saturated and subcooled conditions. Comparison of the saturated case with the experiment is given together with an highlight of the limitations of the model in subcooled cases.