Novel Methods for Modeling Thermochromic Variable Emissivity Surfaces

Thermochromic variable emissivity material (VEM) optical properties (i.e., emissivity and absorptivity) vary in response to material temperature. As a result, these VEMs can provide passive, adaptable heat rejection and temperature regulation for spacecraft thermal engineers. In the future, it is anticipated that these types of materials will become mainstream; however, a significant barrier to their adoption is the lack of means to accurately model VEM behavior using traditional tools. Traditional spacecraft thermal modeling assumes constant surface properties which do not accurately capture the unique variable emissivity nature of VEMs. To overcome this challenge, novel VEM modeling methods were developed in Thermal Desktop. Methods include Radiation Conductor, Dynamic SINDA (Systems Improved Numerical Differencing Analyzer), and Radiation Database. Details of each method are provided with examples of implementation and results.