Understanding Transport Phenomena of Non-Newtonian Fluids-1 — Lesson 2

This lesson covers the concept of transport phenomena of non-Newtonian fluids, focusing on capillary viscometers errors and corrections. It delves into the details of capillary viscometers, their application in measuring the rheology of non-Newtonian fluids, and the equations for shear stress and shear rate. The lesson also discusses the importance of fully developed flow, the impact of wall slip effects, and the significance of kinetic energy losses. It further explains how to correct for end effects and how to interpret and analyze data obtained from capillary viscometers. An example problem is provided to illustrate the application of these concepts.

Video Highlights

01:12 - Explanation of the equations for shear stress and shear rate in capillary viscometers.
04:19 - Explanation of the concept of constant flow rate and constant pressure in capillary viscometers.
21:15 - Discussion on the possible sources of errors in capillary viscometers and ways to correct them.
46:19 - Explanation of the process of obtaining corrected pressure drop and true shear stress in capillary viscometers.

Key Takeaways

• Capillary viscometers are crucial in measuring the rheology of non-Newtonian fluids.
• The shear stress and shear rate at the wall of the capillary are significant parameters.
• The concept of nominal and true shear rates is essential, especially for time-independent non-Newtonian fluids.
• Maintaining a constant flow rate or pressure is crucial in the operation of capillary viscometers.
• Understanding the impact of pressure drop and the importance of fully developed flow is vital.