CHEE 3525 Lecture Notes - Lecture 38: Shear Rate
Document Summary
Absolute or dynamic viscosity: resistance to shear determined by its cohesion and its rate of transfer of molecular momentum du/dy du/dy. Kinematic viscosity: ratio of dynamic viscosity to density. When a real fluid is in contact with a boundary surface, the fluid has the same velocity as the boundary. If the distance between the two surfaces is small, then the rate of change of velocity with position is linear. The velocity gradient is a measure of the velocity change and is defined as u/ y (also called the shear rate). Newtonian: viscosity is a function only of the condition of the fluid. Non-newtonian: viscosity is dependent on the velocity gradient in addition to the condition of the fluid.