A noncrystalline silica model and a primary particle model was built based on the theory of molecular dynamic and the algorithm of its simulation

and it explored how the solid phase thermal conductivity of aerogel was affected by the changes of external environmental conditions and aerogel internal structure. The results of silica aerogel solid phase thermal conductivity under four different enviromental temperatures

namely

300

500

800K and 1200K were obtained. With the enviromental temperature rise the solid phase thermal conductivity increased slightly. The influence of the internal defect of primary particle on the solid phase thermal conductivity of skeleton was discussed. Within the range of porosity

the thermal conductivity of the solid phase decreased with the increase of the porosity. When the porosity increased gradually to 0.26

the model can well characterize the actual situation. The noncrystalline aerogel model and algorithm proposed will provide a reference for the microscale heat transfer analysis and structural design of this material.