Viscosity and mass transport in nonuniform Keplerian disks

G. W. Ojakangas, Richard J. Greenberg

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

A new quantitative formalism describing the dynamics of a Keplerian particulate disk, based on a heuristic description of viscous transport, permits study of rings with a wide range of ensemble and individual particle properties. Here the formalism is developed and applied to the case of a ring with a radial gradient in optical thickness. A steady-state solution for the velocity distribution directly gives the radial mass transport, as well as the viscosity. The formula for viscosity is identical to that derived a decade earlier by Goldreich and Tremaine for a uniform disk, thus validating the assumption by various workers that it could be applied to nonuniform disks, for example in consideration of ringlet instabilities. Our analytical method involves solving a novel form of the Krook equation by separating the distribution of collisional products in phase space into a symmetrical component and a remainder that can be approximated by delta functions. Unlike most past approaches, a Gaussian form for the solution is not assumed. In the case described here, the model is simplified in common with past work (e.g., small, uniform particles and Krook-type treatment of collisions), but the general approach is extendable to less artificially restricted cases.

Original languageEnglish (US)
Pages (from-to)146-171
Number of pages26
JournalIcarus
Volume88
Issue number1
DOIs
StatePublished - 1990

Fingerprint

mass transport
viscosity
Krook equation
heuristics
formalism
analytical method
collision
rings
delta function
optical thickness
particulates
velocity distribution
gradients
collisions
products
distribution
particle
product

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

Viscosity and mass transport in nonuniform Keplerian disks. / Ojakangas, G. W.; Greenberg, Richard J.

In: Icarus, Vol. 88, No. 1, 1990, p. 146-171.

Research output: Contribution to journalArticle

Ojakangas, G. W. ; Greenberg, Richard J. / Viscosity and mass transport in nonuniform Keplerian disks. In: Icarus. 1990 ; Vol. 88, No. 1. pp. 146-171.
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