Newtonian Fluid
Newtonian fluid is a type of fluid that follows Newton's law of viscosity, which states that the shear stress between adjacent fluid layers is proportional to the velocity gradient in the direction perpendicular to the layers. In simpler terms, the viscosity of a Newtonian fluid remains constant regardless of the shear rate applied to it.
**Characteristics of Newtonian Fluid**
- **Constant Viscosity:** The viscosity of a Newtonian fluid remains constant regardless of the shear rate or stress applied to it.
- **Linear Relationship:** The relationship between shear stress and shear rate is linear, making it easy to predict the fluid behavior.
- **Examples:** Common examples of Newtonian fluids include water, air, and most oils.
**Viscosity of Newtonian Fluid**
The viscosity of a Newtonian fluid is represented by a single value, known as the dynamic viscosity or absolute viscosity. It is measured in units of Pascal-seconds (Pa·s) or poise (P). The viscosity of a Newtonian fluid can be calculated by dividing the shear stress by the shear rate.
**Applications of Newtonian Fluid**
Newtonian fluids are commonly used in various engineering applications due to their predictable behavior. Some common applications include:
- **Hydraulic Systems:** Newtonian fluids are used in hydraulic systems where precise control of flow and pressure is required.
- **Pharmaceutical Industry:** Newtonian fluids are used in drug formulation and manufacturing processes.
- **Food Industry:** Newtonian fluids are used in food processing and manufacturing, such as in the production of sauces and syrups.
In summary, Newtonian fluids have constant viscosity, exhibit a linear relationship between shear stress and shear rate, and are used in various engineering applications due to their predictable behavior.