Crater ejecta scaling laws: fundamental forms based on dimensional analysis

Journal Article · Thu Mar 10 04:00:00 EST 1983 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JB088iB03p02485· OSTI ID:6268093

Housen, K R; Schmidt, R M; Holsapple, K A

A model of crater ejecta is constructed using dimensional analysis and a recently developed theory of energy and momentum coupling in cratering events. General relations are derived that provide a rationale for scaling laboratory measurements of ejecta to larger events. Specific expressions are presented for ejection velocities and ejecta blanket profiles in two limiting regimes of crater formation: the so-called gravity and strength regimes. In the gravity regime, ejectra velocities at geometrically similar launch points within craters vary as the square root of the product of crater radius and gravity. This relation implies geometric similarity of ejecta blankets. That is, the thickness of an ejecta blanket as a function of distance from the crater center is the same for all sizes of craters if the thickness and range are expressed in terms of crater radii. In the strength regime, ejecta velocities are independent of crater size. Consequently, ejecta blankets are not geometrically similar in this regime. For points away from the crater rim the expressions for ejecta velocities and thickness take the form of power laws. The exponents in these power laws are functions of an exponent, ..cap alpha.., that appears in crater radius scaling relations. Thus experimental studies of the dependence of crater radius on impact conditions determine scaling relations for ejecta. Predicted ejection velocities and ejecta-blanket profiles, based on measured values of ..cap alpha.., are compared to existing measurements of velocities and debris profiles.

• Research Organization: Shock Physics and Applied Mechanics, Boeing Aerospace Company, Seattle, Washington 98124
• OSTI ID: 6268093
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 88:B3; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CAVITIES
CRATERS
EXCAVATION
IMPACT SHOCK
IMPACT STRENGTH
MECHANICAL PROPERTIES
SCALING LAWS
VELOCITY