Fig. 1. Diagram of a coating containing randomly distributed and identically oriented aluminum flakes

Fig. 2. Comparison of radiative properties of spherical particles with varied size parameters calculated by Siris code and Mie theory (wavelength: 0.6283 μm, refractive index of particles: 1.33+0.5i, refractive index of medium: 1)

Fig. 3. Sketch of the two-flux theoretical model

Fig. 4. Comparison of the spectral emissivity of the coating calculated by two-flux method and Ref. [14]

Fig. 5. Spectral radiative properties of aluminum flakes at different incident angles θ. (a) Absorption cross-section σ_a; (b) Scattering cross-section σ_s; (c) Asymmetry factor g

Fig. 6. Spectral absorptivity of the coating under different orientation angles of aluminum flakes (f_v = 0.1)

Fig. 7. Dependence of spectral absorptivity of the coating with the particle volume fraction f_v and wavelength λ under orientation angles θ of 0, 15°, 30°, 45°, 60°, 70° and 80°

Fig. 8. Dependence of spectral emissivity of the coating with the particle volume fraction f_v and wavelength λ under orientation angles θ of 0, 15°, 30°, 45°, 60°, 70° and 80°

Fig. 9. Dependence of (a) average absorptivity α, (b) average emissivityε, and (c) ratio of absorptivity to emissivity of the coating α/ε with the flake orientation angle θ and volume fraction f_v (contour lines: α/ε = 0.8, 1.0, 1.3)

Fig. 10. Dependence of (a) average absorptivity α, (b) average emissivity ε and (c) ratio of absorptivity to emissivity of the coating α/ε with the thickness d under different flake orientation angle θ (f_v = 0.2)