Accession Number:

AD0671126

Title:

A QUASI-AXISYMMETRIC APPROXIMATION FOR TURBULENT, THREE-DIMENSIONAL JETS AND WAKES,

Descriptive Note:

Corporate Author:

POLYTECHNIC INST OF BROOKLYN N Y DEPT OF AEROSPACE ENGINEERING AND APPLIED MECHANICS

Personal Author(s):

Report Date:

1968-05-01

Pagination or Media Count:

44.0

Abstract:

An approximation is proposed for predicting the mean properties of three-dimensional, incompressible, turbulent jets and wakes. The theory is applicable to the fully developed far field of such flows. Experimental evidence for both jets and wakes dictates the basic arguments comprising the approximation 1 rate of decay of velocity or velocity defect along the axis assumes the axisymmetric value well before the flow field itself becomes axisymmetric, 2 velocity profiles in the far field are similar in both principal planes of the flow field with the similarity variable a function of the growth rate along the pertinent principal axis, and 3 the contours of constant streamwise component of mean velocity are affinely related. These factors are utilized to develop a quasi-axisymmetric approximation which reduces the three-dimensional mean flow equations to the well-known axisymmetric forms. Comparisons with available experimental data reveal uniformly good agreement for both jet and wake flows. Author

Subject Categories:

  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE