Pressure-driven capillary viscometer: fundamental challenges in transient flow viscometry.
We describe an unsteady pressure-driven capillary viscometer, in which the liquid under test is forced through a capillary tube by compressed-air pressure. The principle of operation involves measurement of the driving pressure versus time that decays progressively as the fluid flows and covers continuously a broad shear rate range in a single measurement. The viscosity is determined by curve fitting of the experimental data to the explicit expression for the transient pressure as a function of time. A laboratory bench test shows the validity of the theoretical approach for viscosity determination of both Newtonian and non-Newtonian liquids.
Department of Education in Technology and Science, Technion-Israel Institute of Technology, Haifa 32000, Israel.
Rafael M
RM
Digilov