Affiliations: [a] Department of Aeronautics and Astronautics, Purdue University, W. Lafayette, IN 47907, U.S.A. | [b] Department of Mechanical Engineering and Materials Science, Rice University, Houston, Texas
Note: [*] Current address: Engineering Division, Bldg. 310, Argonne National Laboratory, Argonne, IL 60439, U.S.A.
Note: [**] Formerly at the Department of Aeronautics and Astronautics, Purdue University, W. Lafayette, IN 47907, U.S.A.
Abstract: The results of an investigation of the previously undetermined rheological properties of human semen using a modified, multiple-point capillary viscometer are presented. The design of a viscometer, specifically constructed to give accurate, instantaneous pressure gradient and material flow rate records of biological viscoelastic fluids whose rheological properties are possibly changing with time is given. Using this device, measurements are made on human semen immediately following ejaculation. An analytical scheme for the data reduction, suitable for non-linear viscoelastic fluids of the Maxwell-type, is offered. An expression is developed for a non-linear Maxwell-type viscoelastic fluid flow in a circular tube, relating the material’s elastic properties to the distance of recoil and the pressure gradient. In the case of a power-law elastic behavior this relation couples the wall shear stress with the recoil distance through an apparent shear modulus. Previously established procedures for the viscous response analysis are utilized and an approximate non-dimensional parameter is introduced allowing one to ascertain the relative contributions of the elastic and viscous components to the rate of flow. Results show the elastic and viscous properties of human semen to be functions of time following ejaculation and frequency of ejaculation. The elastic component is found to have a linear response over the shear stress range investigated, whereas the viscous component is found to exhibit a power-law behavior. The final equilibrium state is characterized by Newtonian behavior, with mean absolute viscosity of 3.37 centipoise. Finally, similarity among all cases examined is found for each material property through consideration of a nondimensional time, t∗, determined from semen liquefaction time and time post ejaculation.
DOI: 10.3233/BIR-1977-145-608
Journal: Biorheology, vol. 14, no. 5-6, pp. 277-292, 1977
