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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

A MULTI-LAYERED COATING WITH EMBEDDED SMALL PARTICLES TO IMPROVE SHIELDING OF SPACE VEHICLES FROM INTENSE SOLAR IRRADIATION

Get access (open in a dialog) DOI: 10.1615/IHTC16.nee.021209
pages 7753-7758

Resumo

It has been recently shown that a cloud of micron-sized SiC particles generated during ablation of a composite thermal protection material is a promising way to shield Solar Probe or another space vehicle from thermal radiation of the Sun. A numerical study presented in the paper indicates that an appropriate combination of the ablation enthalpy and particle size depends significantly on the vehicle distance from the Sun. The computational model is based on the Mie theory for spectral radiative properties of particles and the two-flux method for 1-D radiative transfer modeling in the particle cloud. The replacement of particles by action of both the drag force from the ablation gases and radiation pressure is taken into account. The calculations for the transient conjugated heat transfer problem show that highly-porous carbon foams or similar matrix material in combination with small particles comparable in size with the wavelength are more effective at large distances from the Sun because of high scattering albedo of particles and relatively low values of radiative flux. The increase in solar radiation flux at lower part of the vehicle orbit around the Sun makes reasonable the use of stronger matrix materials and larger particles. The latter is explained by a significant sublimation rate of silicon carbide. As a result, a layered thermal protection characterized by increasing of both the ablation enthalpy of a host material and the characteristic particle size with the depth from the irradiated surface of a vehicle can be recommended for applications in space engineering.