Dust-aggregate impact into granular matter: A systematic study of the influence of projectile velocity and size on crater formation and grain ejection

Abstract

Context. Dust impact into granular materials leads to crater formation and material ejection. Aims. The impact of dust aggregates, composed of a number Np of grains, into a granular bed consisting of the same grains is studied as a function of impact velocity v and projectile size Np. No gravitational effects are included. Methods. Granular-mechanics simulations are used to study the outcome of dust-aggregate impacts. The granular bed and the aggregates are composed of silica grains and have filling factor 0.36. Results. Both the crater volume and the ejection yield increase sublinearly with total impact energy. No crater rims are formed. Crater shapes change from hemispheric to elongated when increasing either projectile size or velocity. The crater walls are compacted by the impact within a zone of a size comparable to the crater radius. Ejecta are produced at the edges of the impact; only a small fraction of the ejecta stem from the projectile. The energy distribution of the ejecta follows at high energies a 1/E 2 decay reminiscent of sputtering from atomic targets. The maximum of the distribution is shifted to higher energies for larger projectiles; this is caused by the increasing depth from which ejected grains originate. Conclusions. Due to the dissipative nature of intergranular collisions and the porosity of the target, crater morphology and ejecta yield deviate characteristically from impacts into atomic materials.

The Physics of Protoplanetary Dust Agglomerates. X. High-velocity Collisions between Small and Large Dust Agglomerates as a Growth Barrier

“…To theoretically find a proper mean particle size for their measurements with respect to the erosional effect, each particle size of their distribution function should be weighted with the respective erosional potential and impact velocity. Planes et al (2017) did numerical investigations of agglomerate-projectile impacts into agglomerate targets, which is very similar to our experimental work but has partly substantially different results. The erosion yield obtained by Planes et al (2017) is also directly proportional to the impact velocity of the projectiles and the ejected mass does not contain projectile material.…”

“…Planes et al (2017) did numerical investigations of agglomerate-projectile impacts into agglomerate targets, which is very similar to our experimental work but has partly substantially different results. The erosion yield obtained by Planes et al (2017) is also directly proportional to the impact velocity of the projectiles and the ejected mass does not contain projectile material. Furthermore, their crater depth is proportional to their projectile size and the erosive effect is reduced for larger particles.…”

The Physics of Protoplanetesimal Dust Agglomerates. IX. Mechanical Properties of Dust Aggregates Probed by a Solid-projectile Impact

“…To properly simulate the formation and compaction of regolith surfaces, a good knowledge of the impact physics into granular matter is required. Examples of applications of experimental impact studies such as the one described in this paper are high-velocity impacts into asteroidal surfaces with and without regolith (see, e.g., Beitz et al 2016) or dust-aggregate impacts into granular matter (see, e.g., Planes et al 2017).…”

Análisis de clústeres para simulaciones de mecánica granular mediante algoritmos de aprendizaje automático

“…Understanding the mechanism of these processes in this scale is fundamental when trying to explain the formation of planetary rings, protoplanets, the distributions of powder grain sizes in different scenarios, etc. [6], [7].…”