Fluids are substances that can flow and take the shape of their container. They can be liquids or gases. Fluids behave according to the laws of fluid mechanics, which describe how they move, exert forces, and interact with their surroundings.
Tensors are mathematical objects used to represent physical quantities, such as stress, strain, and velocity, in three-dimensional space. In fluid mechanics, tensors are commonly used to describe the stress and strain of fluids and to solve problems related to fluid flow.
The Navier-Stokes equation is a set of partial differential equations that describe the motion of fluids. It is important in fluid mechanics because it provides a fundamental framework for understanding and predicting the behavior of fluids in various situations, such as fluid flow in pipes or around objects.
Viscosity is a measure of a fluid's resistance to flow. It is a property that determines the rate of deformation of a fluid under an applied force. Fluids with high viscosity, such as honey, are thick and flow slowly, while fluids with low viscosity, such as water, are thin and flow more easily.
Turbulence is a chaotic and irregular flow pattern that occurs in fluids when the speed and direction of flow vary significantly. It is caused by factors such as high velocity, rough surfaces, and changes in pressure. Turbulence can greatly affect fluid flow, making it difficult to predict and control, and can cause energy losses and structural damage in systems such as pipelines and aircraft wings.