Doctoral Dissertations


Ian Radin


"Pressure drop measurements were made on a variety of solid-liquid suspension systems in order to study the effects of particle shape and size, concentration, fluid viscosity and tube diameter on drag reduction. Measurements were made over a wide range of Reynolds numbers in two tubes: 1/4 inch and 1 inch in diameter.

Drag reduction could always be obtained with fibrous additives of length-to-diameter ratio greater than 25-35 if the concentration was sufficiently high. The drag reduction behavior of these suspensions is different from that of high polymer and soap solutions. Laminar flow behavior is stabilized giving lower than normal friction factors and transition to turbulent flow extends over a range of up to two decades or more of Reynolds number. High ℓ /d promotes drag reduction for a given d. Smaller diameter, more flexible fibers, are more effective for drag reduction at equal ℓ /d values. No drag reduction was obtained with spherical, platelet or needle-shaped rigid solid additives.

Concentration studies pointed up the need for measurements over a range of flow rates as the relative drag reducing abilities of different concentrations of additives vary with the Reynolds number. The relative dispersing abilities of fluids of different viscosity apparently affect the drag reducing character of the suspensions at high Reynolds numbers more than viscosity. Contrary to results with polymers and soaps, greater drag reduction was obtained in the l-inch tube than in the 1/4-inch tube at equal suspending fluid Reynolds numbers.

Examination of solid-gas suspension data in the literature shows similar flow behavior. It is believed that electrostatic charges on the particles have a major effect on solid-gas friction factor behavior"--Abstract, pages ii-iii.


Zakin, J. L.

Committee Member(s)

Oetting, R. B.
Patterson, G. K. (Gary Kent), 1939-
Howell, Ronald H. (Ronald Hunter), 1935-
Pagano, Sylvester J., 1924-2006


Mechanical and Aerospace Engineering

Degree Name

Ph. D. in Mechanical Engineering


Petroleum Research Fund


University of Missouri--Rolla

Publication Date



x, 136 pages

Note about bibliography

Includes bibliographical references (pages 87-90).


© 1974 Ian Radin, All rights reserved.

Document Type

Dissertation - Open Access

File Type




Subject Headings

Drag (Aerodynamics)
Surface active agents
Boundary layer

Thesis Number

T 3002

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