Turbulent flow is a pattern of flow, for either fluid gas or liquid, that is undergoing constant change or irregular fluctuations. This term can be used to describe an event that utilizes physics or to describe a fluid process in the realm of medicine.
In the world of physics, turbulent flow is often used to describe a great many fluid events. It can be used to describe the flow of water, such as a river, or the flow of the wind. In both cases, it would seem to the naked eye that everything is moving in one general directions, but in actuality, there is a tremendous amount of turbulence taking place beneath the surface. It is this turbulence that is affecting both magnitude and direction. This is in direct contrast to what is known as laminar flow, which describes a situation where fluid moves along in uniform, smooth layers or paths. Laminar flow is described and usually seen when fluid is running close to a solid surface, such as when water flows through a pipe, or when the fluid has a high level of viscosity, meaning that the fluid is thick and sluggish therefore not able to move quickly. Running lava is a great example of laminar flow and defines a fluid with high-level viscosity.
In the medical world, the term turbulent flow is also used to describe certain events that take place within the human body. A turbulent flow would occur inside a blood vessel that is experiencing an aneurysm, stenosis or other blockage; the sudden change in both speed and direction would cause turbulence within the blood vessels. Without the presence of these types of devastating events, the blood flow inside the blood vessels would otherwise be categorized as having a smooth and steady laminar flow.