Ultraviolet scattering properties of alumina particle clusters at three phase states in aircraft plume

- Based on multi-sphere T matrix method, we calculated the clustered alumina particle scattering characteristics instead of usually be used spherical particle model.
- We discussed the scattering properties of alumina particles in liquid, alpha and gamma phase states.
- We studied the effect of monomer number, fractal dimension and incident wavelength to the scattering phase function of the clustered alumina particles.

We simulate the clusters of alumina particles using the parallel diffusion limited aggregation algorithm (DLA), and solve the scattering matrixes of the alumina particles in different phase states (alpha phase, gamma phase and liquid) through the multiple sphere T matrix method in UV. The effect of the number of monomers, fractal dimension and incident wavelength to the scattering phase function of the clusters of alumina particles is discussed. The results show that the different of the number of monomers, fractal dimensions and incident wavelengths have significant effect on the scattering properties of the clustered alumina particle. The researchers used to make the alumina particle equivalent to the alpha phase spherical particle, but it is too simplistic. We compare the scattering phase functions of the equivalent volume sphere (EVS), the equivalent surface sphere (ESS) and the clusters of alumina particles in three kinds of phase states. The results show that the backward scattering would be overestimated if the alumina particle is equivalent to the alpha phase spherical particle. Accurate phase function calculation in different phase states is very helpful to study the radiation propagation characteristics of aircraft plume.