Deformation and internal flow of a chondrule-precursor molten sphere in a shocked nebular gas

Masayuki Uesugi, Minoru Sekiya, Taishi Nakamoto

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

Chondrule formation due to a nebular shock wave heating is considered. We calculate the apparent gravitational acceleration, internal flow, and deformation of a chondrule precursor molten sphere in the shocked nebular gas. The gravitational acceleration and the internal flow are caused by momentum flux of gas molecules incident on the surface of the sphere. The gravitational acceleration just behind the shock wave is 1.1 to 330 times the terrestrial one. The velocity of the internal flow reaches around 0.1 m s-1 for the pre-shock nebular gas density and the shock wave velocity are 10-6 kg m-3 and 8.7 km s-1, respectively, and then chondrule melt is stirred well by the flow. As a consequence, if there is oxygen heterogeneity in the precursor particle, it must be homogenized by the high speed circulative flow in the molten sphere within a few seconds. The momentum flux also deforms the sphere. The variation of the radius of the molten sphere due to the deformation is less than 1% of the original radius for mm-sized sphere when the sphere re-solidifies. Because we used the hydrodynamic solution with the linear approximation, the applicability of our result of the internal flow is restricted to some region of the parameter space of the shock velocity, the nebular gas density, radius and viscosity of chondrule melt sphere. For larger values of those parameters than typical ones, nonlinear calculations are needed, which is left for future works.

Original languageEnglish
Pages (from-to)493-507
Number of pages15
Journalearth, planets and space
Volume55
Issue number8
DOIs
Publication statusPublished - Jan 1 2003

Fingerprint

chondrule
internal flow
gases
gas
shock wave
shock waves
gas density
radii
momentum
shock
melt
wave velocity
viscosity
hydrodynamics
high speed
heating
oxygen

All Science Journal Classification (ASJC) codes

  • Geology
  • Space and Planetary Science

Cite this

Deformation and internal flow of a chondrule-precursor molten sphere in a shocked nebular gas. / Uesugi, Masayuki; Sekiya, Minoru; Nakamoto, Taishi.

In: earth, planets and space, Vol. 55, No. 8, 01.01.2003, p. 493-507.

Research output: Contribution to journalArticle

@article{99736aded84e48f08bc728b67b3e0668,
title = "Deformation and internal flow of a chondrule-precursor molten sphere in a shocked nebular gas",
abstract = "Chondrule formation due to a nebular shock wave heating is considered. We calculate the apparent gravitational acceleration, internal flow, and deformation of a chondrule precursor molten sphere in the shocked nebular gas. The gravitational acceleration and the internal flow are caused by momentum flux of gas molecules incident on the surface of the sphere. The gravitational acceleration just behind the shock wave is 1.1 to 330 times the terrestrial one. The velocity of the internal flow reaches around 0.1 m s-1 for the pre-shock nebular gas density and the shock wave velocity are 10-6 kg m-3 and 8.7 km s-1, respectively, and then chondrule melt is stirred well by the flow. As a consequence, if there is oxygen heterogeneity in the precursor particle, it must be homogenized by the high speed circulative flow in the molten sphere within a few seconds. The momentum flux also deforms the sphere. The variation of the radius of the molten sphere due to the deformation is less than 1{\%} of the original radius for mm-sized sphere when the sphere re-solidifies. Because we used the hydrodynamic solution with the linear approximation, the applicability of our result of the internal flow is restricted to some region of the parameter space of the shock velocity, the nebular gas density, radius and viscosity of chondrule melt sphere. For larger values of those parameters than typical ones, nonlinear calculations are needed, which is left for future works.",
author = "Masayuki Uesugi and Minoru Sekiya and Taishi Nakamoto",
year = "2003",
month = "1",
day = "1",
doi = "10.1186/BF03351783",
language = "English",
volume = "55",
pages = "493--507",
journal = "Earth, Planets and Space",
issn = "1343-8832",
publisher = "Terra Scientific Publishing Company",
number = "8",

}

TY - JOUR

T1 - Deformation and internal flow of a chondrule-precursor molten sphere in a shocked nebular gas

AU - Uesugi, Masayuki

AU - Sekiya, Minoru

AU - Nakamoto, Taishi

PY - 2003/1/1

Y1 - 2003/1/1

N2 - Chondrule formation due to a nebular shock wave heating is considered. We calculate the apparent gravitational acceleration, internal flow, and deformation of a chondrule precursor molten sphere in the shocked nebular gas. The gravitational acceleration and the internal flow are caused by momentum flux of gas molecules incident on the surface of the sphere. The gravitational acceleration just behind the shock wave is 1.1 to 330 times the terrestrial one. The velocity of the internal flow reaches around 0.1 m s-1 for the pre-shock nebular gas density and the shock wave velocity are 10-6 kg m-3 and 8.7 km s-1, respectively, and then chondrule melt is stirred well by the flow. As a consequence, if there is oxygen heterogeneity in the precursor particle, it must be homogenized by the high speed circulative flow in the molten sphere within a few seconds. The momentum flux also deforms the sphere. The variation of the radius of the molten sphere due to the deformation is less than 1% of the original radius for mm-sized sphere when the sphere re-solidifies. Because we used the hydrodynamic solution with the linear approximation, the applicability of our result of the internal flow is restricted to some region of the parameter space of the shock velocity, the nebular gas density, radius and viscosity of chondrule melt sphere. For larger values of those parameters than typical ones, nonlinear calculations are needed, which is left for future works.

AB - Chondrule formation due to a nebular shock wave heating is considered. We calculate the apparent gravitational acceleration, internal flow, and deformation of a chondrule precursor molten sphere in the shocked nebular gas. The gravitational acceleration and the internal flow are caused by momentum flux of gas molecules incident on the surface of the sphere. The gravitational acceleration just behind the shock wave is 1.1 to 330 times the terrestrial one. The velocity of the internal flow reaches around 0.1 m s-1 for the pre-shock nebular gas density and the shock wave velocity are 10-6 kg m-3 and 8.7 km s-1, respectively, and then chondrule melt is stirred well by the flow. As a consequence, if there is oxygen heterogeneity in the precursor particle, it must be homogenized by the high speed circulative flow in the molten sphere within a few seconds. The momentum flux also deforms the sphere. The variation of the radius of the molten sphere due to the deformation is less than 1% of the original radius for mm-sized sphere when the sphere re-solidifies. Because we used the hydrodynamic solution with the linear approximation, the applicability of our result of the internal flow is restricted to some region of the parameter space of the shock velocity, the nebular gas density, radius and viscosity of chondrule melt sphere. For larger values of those parameters than typical ones, nonlinear calculations are needed, which is left for future works.

UR - http://www.scopus.com/inward/record.url?scp=20644470339&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=20644470339&partnerID=8YFLogxK

U2 - 10.1186/BF03351783

DO - 10.1186/BF03351783

M3 - Article

AN - SCOPUS:20644470339

VL - 55

SP - 493

EP - 507

JO - Earth, Planets and Space

JF - Earth, Planets and Space

SN - 1343-8832

IS - 8

ER -