Effects of Collectively Induced Scattering of Gas Stream by Impurity Ensembles: Shock-Wave Enhancement and Disorder-Stimulated Nonlinear Screening

TL;DR

This paper investigates how collective scattering by impurity ensembles in a gas stream can amplify shock waves and nonlinear effects, revealing new phenomena like disorder-stimulated scattering and shock front stopping.

Contribution

It introduces the concept of collective scattering effects in impurity ensembles, showing how disorder and fragmentation enhance gas stream scattering and shock wave dynamics.

Findings

Scattering can be significantly amplified by nonlinear collective effects.

Disordered impurity clusters produce stronger scattering and faster shock waves.

Steady-state density profiles can form as residual perturbations after shock passage.

Abstract

We report on specific effects of collective scattering for a cloud of heavy impurities exposed to a gas stream. Formation is presented of a common density perturbation and shock waves, both generated collectively by a system of scatterers at sudden application of the stream-inducing external field. Our results demonstrate that (i) the scattering of gas stream can be essentially amplified, due to nonlinear collective effects, upon fragmentation of a solid obstacle into a cluster of impurities (heterogeneously fractured obstacle); (ii) a cluster of disordered impurities can produce considerably stronger scattering accompanied by enhanced and accelerated shock wave, as compared to a regularly ordered cluster. We also show that the final steady-state density distribution is formed as a residual perturbation left after the shock front passage. In particular, a kink-like steady distribution profile can be formed as a result of shock front stopping effect. The possibility of the onset of solitary diffusive density-waves, reminiscent of precursor solitons, is shown and briefly discussed.