THE MOMENTUM EQUATION OF A SOLID-FLUID SYSTEM,

Abstract

The report examines two-phase flows such as those occurring in fluid devices operating with rocket engine exhausts. The momentum interaction between the two phases of a solid-fluid flow has traditionally been reduced to a body force term in the Navier-Stokes equations with the implication that this interchange is symmetric and does not depend on the characteristics of the mixture, thus failing to describe completely the dependence of the momentum exchange upon such parameters as relative Reynolds number, mass loading ratio, etc. The report redefines the problem in terms of a mathematical model consisting of spherical particles with a statistical size and velocity distribution. A logical procedure is followed by defining rigorously the different characteristic scales in the flow, by taking statistical and space averages of the equation of motion of both phases at each of the scales, and finally by separating the effect of the particles as 'internal' boundary conditions on the fluid from those of the 'external' boundary conditions (e.g. pipe wall). This yields a momentum equation with coefficients which are a function of the mixture parameters. (Author)

Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1967
Accession Number
AD0650399

Entities

People

  • Elisabeth D. Martínez

Tags

Communities of Interest

  • Weapons Technologies

DTIC Thesaurus Topics

  • Boundaries
  • Equations
  • Flow
  • Fluid Flow
  • Mathematical Models
  • Momentum
  • Navier Stokes Equations
  • Particles
  • Reynolds Number
  • Rocket Engines
  • Two Phase Flow

Readers

  • Fluid Dynamics.
  • Regression Analysis.

Technology Areas

  • Space
  • Space - Hall-Effect Thruster