Pulsatile laminar flow separation in an exponentially diverging tube
Abstract
A laser Doppler anemometer technique was developed and used to study steady and unsteady flow through rigid circular tubes. An experimental arrangement was presented which includes a design which significantly reduced beam refraction effects as the laser beams pass through the circular glass tube. A Tektronix 4051 data acquisition system was used to acquire the data, process it and display nondimensional axial velocity profiles on a digital plotter. It was found in steady flow through a diverging circular channel that a threshold Reynolds number existed for which the flow separated initially at the furthest downstream end of the channel divergence. With increasing Reynolds number above threshold, the point of flow separation defined by Prandtl's criterion moved upstream, such that for any given axial location x sub i, there corresponded a characteristic Reynolds number at which the flow was completely separated downstream of x sub i. Upstream, the flow remained laminar and attached.
 Publication:

Ph.D. Thesis
 Pub Date:
 February 1979
 Bibcode:
 1979PhDT........54W
 Keywords:

 Exponential Functions;
 Flow Stability;
 Laminar Flow;
 Separated Flow;
 Anemometers;
 Flow Measurement;
 Flow Velocity;
 Nonlinearity;
 Velocity Distribution;
 Fluid Mechanics and Heat Transfer