RESUMO

An effect of shielding of an intense solar radiation towards a solar probe with the use of micron-sized particles generated during ablation of a special composite thermal protection material is estimated on the basis of an approximate solution to a conjugate heat transfer problem. The spectral radiative properties of particles are calculated using the Mie theory, and the two-flux model is used for the radiative transfer calculations in the particle cloud. A computational model for the dynamics, heating, and evaporation/sublimation of small particles takes into account the drag force from a rarefied moving from the sublimating composite material, the light pressure effect and the radiative heating/cooling of absorbing and scattering particles. A preliminary numerical heat transfer analysis indicates that implementation of silicon carbide or similar particles into a thermal protection and the resulting generation of a rarefied particle cloud can be considered as a promising way to protect the solar probe from the intense thermal irradiation. This shielding effect is expected to be important to decrease the minimum working distance of the space vehicle from the solar photosphere.