Types Of Flow
Laminar and Turbulent Flow
What are the two main fluids?
What is Laminar Flow?
Daniel Bernouilli (1700-1782) was an expert in medicine, animals, plants, physics and mathematics. He showed that as water or another liquid flows from a wide pipe into a narrower one, the speed of flow becomes faster; and the liquid also has less pressure. This effect is known as the Bernouilli's principal. It is used in many kinds of engineering and technology, such as the design of aircraft wings, so they provide a lifting force as they move through the air.
Examples Of Laminar Flow:
Northrop X-21
The Northrop X-21A an aerodynamic structure was an experimental aircraft designed to test wings with laminar flow control. This structure needed a body with an aerodynamic shape and soft edges, so that the air can smoothly and easily go past the plane; so that it can cut through any fluid too. The Northrop X-21 can fly father on less fuel because laminar flow allows fluids to move quickly with less energy. The designers designed this plane by using 80% of laminar flow on the wings of the plane, then the overall drag of the plane was reduced by 25%; so that it doesn't create turbulence. So, the result of the maximum speed of the plane was 487kn-(knot unit).
Bullet
A bullet is a perfect example of an aerodynamic shape because it is able to cut through the air without any resistance to flow. When a person pulls the trigger of a gun, the bullet is able to shoot out, with a fast speed and with less energy, because the bullet gets most of its power from the gun when the trigger is pulled.
Dolphin
A dolphin has an aerodynamic shape because its skin is able to reduce rubbing against water, since their skin is very smooth and it can easily go past liquids; without letting the water decrease its resistance to fluid flow.
What is Turbulent Flow?
Examples Of Turbulent Flow:
Golf Ball
The dimples on a golf ball decreases the drag on the ball as it flies through the air, because the dimples of the ball scoops the air around the ball; which reduces the drag. By reducing the pressure, pulling back at the golf ball from behind (eddy). When the golf ball gets hit by the putter, the ball is able to create lift when there is a backspin on the ball as it flies through the air (turbulence).
Smoke
Smoke rising from a cigarette is turbulent flow. As you could see in the diagram, for the first few centimetres, the flow is laminar; but then it turns to turbulent flow because the fluid mixes into different currents (becomes irregular).
Blood Clots
Turbulence can be found in the human body. In a healthy body, blood flows smoothly through arteries (laminar flow). Over time, material called plaque can build up in arteries. Plaque build-up creates turbulence in the blood flow. Turbulent blood flow can cause blood clots. These blood clots can block the arteries and cause heart attacks or strokes.