Table 1.
Physical properties of the tested bed material.
Fig 1.
1–rifle; 2–structure to ensure rifle stability during the shot; 3–sand container; 4–table with containers for collecting ejected grains of sand; 5–high-speed cameras; 6–protection plate against propellant gases; 7–front lighting LED lamp.
Fig 2.
Elements used in the crater analysis.
(A) example crater after the impact at a velocity of ~700 m∙s-1 into a <2 mm fraction sand bed; (B) example of a crater section analysis; (C) cross-section of a crater with bed deformation parameters indicated.
Fig 3.
Description of the ejecta curtain based on high-speed camera imaging.
Symbols: db−base diameter, α –angle of curtain wall.
Fig 4.
(A) maximum crater depth; (B) crater diameter; and (C) maximum rim height. Data are mean values ± standard deviation. The letters refer to the statistical comparison (post hoc Tukey’s HSD test): the same letters–no statistically significant differences.
Fig 5.
Depth-to-diameter ratio of craters for individual sand fractions.
By interpolating straight lines, the intersection at the origin of the graph was forced. R2 represents the coefficient of determination.
Fig 6.
Average angle of inclination of the curtain walls.
Data are mean values ± standard deviation. The letters refer to the statistical comparison (post hoc Tukey’s HSD test): the same letters–no statistically significant differences.
Fig 7.
(A) base diameter of the spreading curtain in subsequent moments in time; (B) curtain expansion velocity in subsequent moments in time. Data are mean values ± standard deviation. The standard deviation bars on graphs are very small and coincide with the symbols. There are no significant differences between the sand fractions in each moment in time step.
Fig 8.
Estimated mass of ejecta transported beyond the bed container (i.e. >310 mm from the impactor strike) for individual tested bed grain-size fractions.
Data are mean values ± standard deviation. The letters refer to the statistical comparison (post hoc Tukey’s HSD test): the same letters–no statistically significant differences.
Table 2.
Maximum distances from the impact point to which sand was moved during impactor strike.
Fig 9.
Impactor penetration depth in sand beds with varying grain sizes.
Data are mean values ± standard deviation. The letters refer to the statistical comparison (post hoc Tukey’s HSD test): the same letters–no statistically significant differences.
Fig 10.
Dependence of the dimensionless scaled crater volume on non-dimensional scaled gravity.