The chaotic flow of fluids in all directions is known as turbulent flow. When a fluid exhibits a turbulent flow, the adjacent layers of the fluid get mixed with each other and do not move parallel to each other. The turbulent flow of the fluid indicates that the fluid flow does not follow a straight line, but it follows a haphazard zig-zag pathway. Reynolds number is used as a criterion that decides whether the flow of fluid is laminar or turbulent. If the Reynolds number of fluid is greater than 4000, it is capable of exhibiting turbulent flow. A turbulent flow usually occurs when the velocity with which the fluid flows is significantly high. It also depends on the diameter of the outlet so that the larger be the diameter, the more is the turbulent flow. The viscosity of the fluid is indirectly proportional to the turbulent flow.
Examples of Turbulent Flow
You must have experienced turbulence while travelling on an aeroplane. Turbulence or the turbulent flow of air means that the particles of air move randomly and get mixed with each other, unlike the laminar flow of air, which means that there exists little or no mixing of the gaseous particles. The various factors causing or affecting turbulence during the aircraft include physical, thermal, or mechanical factors.
The smoke particles coming out of the ignited tip of a cigarette or an incense stick do not get mixed with each other for the first few centimetres, but after travelling some distance, the smoke particles get mixed and the smooth flow of the smoke turns chaotic. This implies that the flow of the smoke is laminar for the first few centimetres, and then it becomes turbulent. Hence, smoke coming out of a cigarette or an incense stick is an example of both laminar and turbulent flow.
The swirls and the waves observed in a silently flowing river are some of the best examples of turbulent flow in daily life. These geophysical flows are mostly influenced due to the presence of an obstacle in the normal pathway of the flowing fluids. The other factors leading to the turbulent flow include the velocity of the flow. The more the flow velocity, the more is the turbulent flow.
4. Blood Flow in Arteries
The blood flowing in the arteries follows a turbulent flow. The curve in the aorta causes the blood flow to get bend, thereby causing the blood cells to get mixed with each other. This leads to a turbulent flow. Sometimes a bulge in the arteries also induces a turbulent blood flow. This also increases radial pressure and shear stress on the artery wall.
When a tap or a faucet is thoroughly opened, the water tends to flow out at a great speed. Due to the high velocity with which the fluid flows, the adjacent layers of the fluid get mixed with each other, and the flow becomes chaotic. This chaotic nature of the flow implies the existence of turbulent flow. Hence, the water flowing through a tap, water pump, or turbine is a prominent example of turbulent flow.
6. Flow of Fluid under an Obstacle
When an obstacle is introduced in between the laminar flow of a fluid, the flow gets transformed into turbulent flow. For example, when a golf ball is put under a tap, the laminar flow of water gets disrupted. The flow of water above the ball stays laminar; however, the flow below the obstacle or the ball turns turbulent.
7. Air from Fan/AC
The air coming from a fan or an air conditioner does not flow in a straight line. It gets circulated inside the room with the help of rotating blades of the fan. This means that the flow of air inside the room is chaotic. The particles or dust and air get mixed with each other. Hence, the flow of air from a fan or an air conditioner is yet another example of the turbulent flow of fluids in real life.
8. Car Exhaust
The smoke coming out of the exhaust pipes of a car is a classic example of turbulent flow in everyday life. The smoke particles do not stay separated from each other, instead, they get mixed and flow in a random zig-zag manner, thereby displaying the turbulent flow.