Journal of Fluid Mechanics

The measurement of velocity gradients in laminar flow by homodyne light-scattering spectroscopy

G. G.  Fuller a1, J. M.  Rallison a1 1 , R. L.  Schmidt a1 2 and L. G.  Leal a1
a1 Department of Chemical Engineering, California Institute of Technology, Pasadena, California 91125

Article author query
fuller gg   [Google Scholar] 
rallison jm   [Google Scholar] 
schmidt rl   [Google Scholar] 
leal lg   [Google Scholar] 


A technique for measuring velocity gradients in laminar flows by homodyne light scattering is presented. A theory which describes the light-scattering spectrum is derived that includes the effects of different types of linear flow fields, particle diffusion and the intensity profile in the scattering volume. The conditions which must be satisfied in order that the theory describe the experimental situation are outlined and complementary experiments are performed which both verify the theory and apply the technique. Verification is provided using the flow in a Couette device, and the flow due to single rotating cylinder in a large bath of fluid. The technique is then applied to measure the spatial variation of the shear rate in a four-roll mill.

(Published Online April 19 2006)
(Received March 5 1979)
(Revised March 12 1980)


1 Department of Applied Mathematics and Theoretical Physics, University of Cambridge.

2 Chevron Oil Field Research, La Habra, California.