Kathryn L Mccarthy

US Patent:

55325939, Jul 2, 1996

Filed:

Nov 1, 1993

Appl. No.:

8/146497

Inventors:

James E. Maneval - Lewisburg PA
Kathryn L. McCarthy - Davis CA
Michael J. McCarthy - Davis CA
Robert L. Powell - Sacramento CA

Assignee:

The Regents of The University of California - Oakland CA

International Classification:

G01V 300

US Classification:

324306

Abstract:

An apparatus and method for obtaining rheological information about a fluid using nuclear magnetic resonance is disclosed herein. A fluid flowing through a tube is subjected to nuclear magnetic resonance imaging signals to obtain the velocity profile of the fluid. The pressure gradient between two points along the tube is also obtained. The shear rate is then determined from the velocity profile, and the shear stress is determined from the pressure gradient. From a single velocity profile, data is obtained over shear rates ranging from zero at the center of the tube to the maximum shear rate at the tube wall. Alternatively, the velocity spectrum can be obtained and used in the same manner. The shear stress versus shear rate curve can thereby be obtained from a single nuclear magnetic resonance image taken at a specific value of the pressure gradient.