Numerical simulation of white double-layer coating with different submicron particles on the spectral reflectance

- The double-layer coating has a great influence on both thermal and aesthetic aspects.
- The double-layer coating performs better than the uniform one with single particles.
- The volume fraction, particle diameter and substrate conditions are optimized.

The spectral selective coating is becoming more and more popular against solar irradiation not only in keeping the coated objects stay cool but also retain the appearance of the objects by reducing the glare of reflected sunlight. In this work a numerical study is investigated to design the double-layer coating with different submicron particles to achieve better performance both in thermal and aesthetic aspects. By comparison, the performance of double-layer coating with TiO2 and ZnO particles is better than that with single particles. What's more, the particle diameter, volume fraction of particle as well as substrate condition is also investigated. The results show that an optimized double-layer coating with particles should be the one with an appropriate particle diameter, volume fraction and the black substrate.