Experimental and Theoretical Study of Variable Density Multilayer Insulation (VDMLI) at Different Cold Boundary Temperatures

Cryogenic propellant will play an important role in the future aerospace field because of its superior properties. The zero boil off (ZBO) storage of cryogenic propellant is the key of its long-term on orbit storage. Variable density multilayer insulation material (VDMLI) is one of the effective passive thermal protection technologies for cryogenic propellant storage tanks. The theoretical and experimental study on the thermal performance of VDMLI can provide reliable guarantee for its practical engineering application. A concentric cylindrical calorimeter is designed and built to measure the thermal performance of the VDMLI at low temperature. The effects of cold boundary temperature on the performance of the VDMLI have been analyzed. According to the layer by layer model, the theoretical model of the VDMLI is established to predict the thermal performance of the VDMLI, and it has been verified by experiments.