Date of Award


Degree Type


Degree Name

Master of Engineering (ME)


Mechanical Engineering


G. F. Round


I. A. Feuerstein


This dissertation reports the development of a flow visualisation technique which was used to study the flow pattern generated by an abrupt expansion in a circular section conduit, Experiments were performed at Reynolds numbers (based on upstream tube diameter) ranging from 222 to 755 and for tube diameter ratios of 0.63, 0.79 and 0.93.

Velocity profiles were obtained at each of two different stations beyond the vortex and these were used as upstream boundary conditions for the linearized axial Navier-Stokes equation for the purpose of predicting development lengths. A correlation was obtained for development length as follows:

L/D = 0.27 Re⁰˙⁹⁴, D [1- (d/D)²˙⁷⁷] Measurements of vortex length were made for a tube diameter ratio of 0.63 and the results correlated in the form

xR/h = 0.048 Re¹˙¹ d

Hence both vortex length and development length increase almost linearly with Reynolds number.