Insulation performance of foam during the terrestrial and ascent period

Highlights: • The minimum thickness of foam for different cryogens are predicted. • The unsteady heat transfer through foam is studied for the diffusion of CO₂. • The transient performance of foam is investigated with the variable physical properties considered. • The performance comparison between foam and foam/MLI is made. To effectively reduce heat leakage, foam insulation is widely used in refrigeration, energy, chemical, cryogenic system and pipe engineering. The present study is aimed to investigate the thermal performance of foam on cryogenic storage system under variable environmental parameters. The heat transfer model through the foam is introduced in detail. The minimum thicknesses of foam for different cryogens are calculated under the influence of the external free convection during the terrestrial condition. Meanwhile, with carbon dioxide diffusion out of and air invasion in the foam cells, the related unsteady process is studied with coupling the mixture gas heat conduction and the external free convection. While during the liftoff of rocket, foam insulation is subjected to the forced aerodynamic heating. The transient thermal performance of foam is particularly investigated under the influence of aerodynamic heating, with the variable physical properties, flight velocity and acceleration, and environmental parameters considered. Finally, the performance comparison between foam and foam/Multilayer insulation is made. Some valuable conclusions are obtained. The present study is of significance to the insulation design for cryogenic fuel storage.