Jetting in Oblique, Asymmetric Impacts

Miller, Gregory H.

doi:10.1006/icar.1998.5945

Cited by 15 publications

(17 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The pressure gradient is in the direction to change the deflection angles to those predicted in the free-slip assumption. In reality, the boundary may not strictly follow either boundary condition but may undergo oscillation as observed in explosive welding experiments [e.g., El-Sobky, 1983], analytical calculations [e.g., Godunov et al, 1970], and numerical simulations [Miller, 1998]. Nevertheless, impact experiments of asymmetric collisions using cone-shaped projectiles and flat targets by Allen et al [1959] show that the critical condition is predicted well by the asymmetric collision model with the freeslip boundary condition assumed by Walsh et al [1953].…”

Section: Asymmetric Jettingmentioning

confidence: 99%

“…Because adiabatic compression does not contribute to an increase in thermal energy, the contrast in degree of heating in Figure 13 would be increased further when the effect of coincidence of stagnation pressure is taken into account. Consequently, uncertainty in the method by Kieffer [1977] [Miller, 1998]. Because such oscillatory motion of the material boundary gives rise to motion of shock fronts around the collision point, the effective impact velocity of incoming flow with respect to the shock front will also fluctuate.…”

Section: Model Reassessmentmentioning

confidence: 99%

“…There are two factors accounting for this discrepancy. First, when either the target or the projectile meets a jetting condition, the other may be mixed into a jet by a Kelvin-Helmholtz instability [Miller, 1998] and/or a viscous drag force acting along the material boundary between the projectile and target. Such mixing will make the transition in the mass ratio of the jetting material gradual, rather than sudden as expected by Ang [1990].…”

Section: Model Reassessmentmentioning

confidence: 99%

See 2 more Smart Citations

Spectroscopic characterization of hypervelocity jetting: Comparison with a standard theory

Sugita¹,

Schultz²

1999

J. Geophys. Res.

View full text Add to dashboard Cite

Abstract. Symmetric collision between two identical plates has yielded successful theoretical models for the jetting process. Consequently, assessment of impact jetting at planetary scales has been largely based on the theories developed for such specific types of collisions. Little experimental work has been done, however, to measure both temperature and target-to-projectile mass ratio of jetting created by spherical projectiles impacting planar targets, which typify planetary impacts. The goal of this study is to examine the validity of applying planar-impact theories to jetting due to impacts of spherical projectiles into planar targets. Using a newly developed spectroscopic approach, we observe jetting created by Copper spheres impacting planar dolomite targets at hypervelocities. In contrast with previous experiments using quartz projectiles, the observed mean temperatures of jets due to copper projectiles does not correlate well with the vertical component of impact velocity. Instead, the observed temperatures of jets show much better correlation with impact velocity than the vertical component of impact velocity and impact angle. The experiments also reveal that the target-to-projectile mass ratio within a jet increases with impact angle (measured from the horizontal). In order to understand the significance of these experimental results, they were then compared with a jetting model for asymmetric collisions based on standard theories. Such a comparison indicates qualitative consistencies, such as complete vaporization of the carbonate target (as opposed to mere degassing of carbon dioxide due to incomplete vaporization of carbonate) and higher target-to-projectile mass ratio in a jet at higher impact angles. Quantitative comparison, however, also reveals significant inconsistencies between theory and experiments, such as an impact-angle effect on jet temperature and a correlation in jet temperatures between projectile and target components. In order to resolve these inconsistencies, new factors such as viscous shear heating and the nonsteady state nature of the jetting processes may need to be considered.

show abstract

Section: Asymmetric Jettingmentioning

confidence: 99%

Section: Model Reassessmentmentioning

confidence: 99%

Section: Model Reassessmentmentioning

confidence: 99%

See 1 more Smart Citation

Spectroscopic characterization of hypervelocity jetting: Comparison with a standard theory

Sugita¹,

Schultz²

1999

J. Geophys. Res.

View full text Add to dashboard Cite

show abstract

“…The emission velocities of a large part of these fragments are low, consequently they will acquire orbits "similar" to Iapetus' and they might impact Iapetus again. Neverthless, we expect a high velocity ricochet for very grazing impacts (see Miller 1998). TYPE2 impacts at β g = 15…”

Section: Remarks and Conclusionmentioning

confidence: 95%

“…This latter case, for example, may be due to a slight focusing of the ejecta or the creation of collimated jets due to a strongly non-central collision (see Martelli et al 1993;Miller 1998). The fragments able to reach Iapetus are those ejected towards Hyperion's motion direction.…”

Section: Transfer Of Massmentioning

confidence: 99%

Hyperion-Iapetus: Collisional relationships

Marchi

Barbieri

Dell’Oro

et al. 2002

A&A

View full text Add to dashboard Cite

Abstract. In this paper, we will deal with one of the most fascinating problems of the Solar System: the origin of the double face of Iapetus, where one half of the satellite is significantly brighter than the other. The "transfer of mass" process (see Marchi et al. 2001) may be a viable explanation for the visible dichotomy. In this process a satellite undergoes mass transfer from other satellites belonging to the same system. We analyze the pair Hyperion-Iapetus and suggest a possible explanation for the formation of the dark region, which is also known as Cassini Regio.

show abstract

Dynamics of hypervelocity jetting during oblique impacts of spherical projectiles investigated via ultrafast imaging

Kurosawa

Nagaoka

Senshu

et al. 2015

J. Geophys. Res. Planets

View full text Add to dashboard Cite

A series of hypervelocity impact experiments was conducted in a new laboratory at Planetary Exploration Research Center of Chiba Institute of Technology (Japan). We present the results of high-speed imaging observations of impact jetting during blunt-body penetration under oblique impacts. The observations were sampled at a frame rate of 100 ns frame À1 , which is much shorter than the characteristic time of projectile penetration under our experimental conditions. The maximum jet velocity was obtained as a function of both impact velocity and the contrast of shock impedance between a projectile and target, enabling us to test theoretical models of impact jetting during oblique impacts of spherical projectiles. We find that the jet velocities measured in this study are much slower than the prediction by the standard theory based on the previous experimental/theoretical results of collisions between two metal plates. A decaying shock pressure during blunt-body penetration is a possible origin of the discrepancy. We also present a new formulation of the jet velocity with the equations of state for realistic materials. The particle velocities of ejected materials from a free surface are calculated using the Riemann invariant along the isentropes and the Tillotson equations of state in this study. Based on the extremely high velocity of the jet, we point out that impact jetting might contribute to chemistry near the ground surface of planets/satellites with a thick atmosphere, such as Titan.

show abstract

Jetting in Oblique, Asymmetric Impacts

Cited by 15 publications

References 20 publications

Spectroscopic characterization of hypervelocity jetting: Comparison with a standard theory

Spectroscopic characterization of hypervelocity jetting: Comparison with a standard theory

Hyperion-Iapetus: Collisional relationships

Dynamics of hypervelocity jetting during oblique impacts of spherical projectiles investigated via ultrafast imaging

Contact Info

Product

Resources

About