Search results
5 dni temu · Viscosity is a physical quantity that describes a fluid’s resistance to flow. It is a property that resists the relative displacement of the different layers of the fluid. It can be considered as the fluid friction occurring inside the fluid due to the internal friction between the molecules.
The viscosity of a fluid is a measure of its resistance to deformation at a given rate. [1] For liquids, it corresponds to the informal concept of "thickness": for example, syrup has a higher viscosity than water. [2] Viscosity is defined scientifically as a force multiplied by a time divided by an area.
The precise definition of viscosity is based on laminar, or nonturbulent, flow. Before we can define viscosity, then, we need to define laminar flow and turbulent flow. Figure shows both types of flow. Laminar flow is characterized by the smooth flow of the fluid in layers that do not mix.
If a sphere is dropped into a fluid, the viscosity can be determined using the following formula: \(\begin{array}{l}η=\frac{2ga^2(∆ρ)}{9v}\end{array} \) Where ∆ ρ is the density difference between fluid and sphere tested, a is the radius of the sphere, g is the acceleration due to gravity and v is the velocity of the sphere.
The precise definition of viscosity is based on laminar, or nonturbulent, flow. Before we can define viscosity, then, we need to define laminar flow and turbulent flow. Figure 12.10 shows both types of flow. Laminar flow is characterized by the smooth flow of the fluid in layers that do not mix.
17 wrz 2024 · Viscosity is a major factor in determining the forces that must be overcome when fluids are used in lubrication and transported in pipelines. It controls the liquid flow in such processes as spraying, injection molding, and surface coating.
The internal friction that causes this velocity gradient is called the viscosity of the fluid. For sufficiently small velocities the flow will be laminar i.e. layered. One can show that laminar flow leads to a parabolic distribution of velocities across a pipe with a circular cylindrical cross section.
