ON MASS ENTRAINMENT BY JETS. PHASE I. PRELIMINARY INVESTIGATIONS.

Abstract

This report speculates on the nature of mass entrainment by free jets effluxing into a quiescent medium of equal density. The complex dynamic of the jet boundary at laminar Reynolds numbers is examined. Data has been obtained concerning the frequency of vortex shedding, vortex growth rates, and total roll-up angles. This data was obtained in a water table using pulsed hydrogen bubble generation. An estimate is made of the rate of mass entrained by the 'scooping-up' of the surrounding fluid by the developing vortex structures. The effect of disturbances (sound waves) on the jet is discussed in the light of the evidence of substantial increase in the entrainment rate of an artificially excited jet. A reattaching jet experiment is proposed to measure the effect of sound on entrainment rates. Preliminary data is presented on the attachment point versus entrainment rate for a ventilated Coanda bubble at Reynolds nos. of 1060, 1380, 2790. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1966
Accession Number
AD0637204

Entities

People

  • Elisabeth D. Martínez

Tags

DTIC Thesaurus Topics

  • Acoustic Propagation
  • Acoustic Waves
  • Attachment
  • Boundaries
  • Demographic Cohorts
  • Entrainment
  • Fluid Flow
  • Frequency
  • Frequency Shift
  • Groundwater
  • Hydrogen
  • Physics
  • Reynolds Number
  • Sound Waves
  • Vortex Shedding
  • Vortices

Fields of Study

  • Physics

Readers

  • Business Analytics
  • Fluid Mechanics and Fluid Dynamics.