CaltechAUTHORS
  A Caltech Library Service

Angular momentum transfer in low velocity oblique impacts: Implications for asteroids

Yanagisawa, Masahisa and Eluszkiewicz, Janusz and Ahrens, Thomas J. (1991) Angular momentum transfer in low velocity oblique impacts: Implications for asteroids. Icarus, 94 (2). pp. 272-282. ISSN 0019-1035. https://resolver.caltech.edu/CaltechAUTHORS:20141027-101823852

Full text is not posted in this repository. Consult Related URLs below.

Use this Persistent URL to link to this item: https://resolver.caltech.edu/CaltechAUTHORS:20141027-101823852

Abstract

The efficiency of angular momentum transfer ζ in low velocity oblique impacts was studied experimentally. ζ is defined as the fraction of incident angular momentum transferred to the rotation of the target. Plaster, mortar, cement, and one granite target were studied. Lead and aluminum projectiles were used. Only cratering impacts were considered. ζ was found to decrease with increasing incidence angle φ (relative to the surface normal). For example, for impacts into cylindrical mortar targets a least-squares fit of the form ζ = A(cos φ)β with A = 0.9 and β = 1.7 was found to match the data points reasonably well. In addition, β decreased from 1.9 to 1.4 as the kinetic energy density ϵ (= kinetic energy of the projectile/projectile volume) increased from 0.5 to 1.8 × 10^9 J m^(−3). This suggests that more energetic impacts transfer angular momentum more efficiently. ζ decreased as the indentation hardness H of the target increased: at φ ∼ 35°, ζ = 0.07 for granite (H = 850 kg mm^(−2) and ζ = 0.7 for plaster (H = 7.5 kg mm^(−2)). Cement and mortar (H = 76 kg mm^(−2)) yielded intermediate values, although the values for cement (ζ ∼ 0.3) were appreciably lower than for mortar (ζ ∼ 0.6). In all cases where the velocity of the ricochetted projectile was determined, the fraction of angular momentum carried away by ejecta was found to be less than 30%. Finally, the results were only weakly dependent on the material of the projectile.


Item Type:Article
Related URLs:
URLURL TypeDescription
http://dx.doi.org/10.1016/0019-1035(91)90227-K DOIArticle
http://www.sciencedirect.com/science/article/pii/001910359190227KPublisherArticle
Additional Information:© 1991 Academic Press. Inc. Received January 28, 1991: Revised August 22, 1991. We thank Dr. W. Knauss for the use of the framing camera, M. Long for his assistance in the experiments, and W. Yang for conducting the hardness measurements. We thank H. J. Melosh for providing the Kornhauser (1964) reference to us. The careful reviews by P. Cerroni and A. Fujiwara are also appreciated. The experimental work was supported by NASA and M.Y. derived support from the Japanese Ministry of Education. Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, contribution 4982.
Funders:
Funding AgencyGrant Number
NASAUNSPECIFIED
Ministry of Education, Culture, Sports, Science and Technology (MEXT)UNSPECIFIED
Other Numbering System:
Other Numbering System NameOther Numbering System ID
Caltech Division of Geological and Planetary Sciences4982
Issue or Number:2
Record Number:CaltechAUTHORS:20141027-101823852
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20141027-101823852
Official Citation:Yanagisawa, M., Eluszkiewicz, J., & Ahrens, T. J. (1991). Angular momentum transfer in low velocity oblique impacts: Implications for asteroids. Icarus, 94(2), 272-282. doi: http://dx.doi.org/10.1016/0019-1035(91)90227-K
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:50840
Collection:CaltechAUTHORS
Deposited By: Joanne McCole
Deposited On:27 Oct 2014 18:31
Last Modified:03 Oct 2019 07:27

Repository Staff Only: item control page