Blasius boundary layer

Imagine you are playing with a toy car in a pool of water. When you move the car through the water, the water molecules get disturbed and stick to the toy car. This creates a thin layer of water around the car, called a boundary layer.

Now imagine the same thing happening with a real car driving through the air. As the car moves forward, it pushes air molecules out of the way and creates a boundary layer of air around the car.

The Blasius boundary layer is a special type of boundary layer that happens when air flows smoothly over a flat plate. In this case, the boundary layer forms into three different layers: thin viscous layer, momentum layer and turbulent layer.

The first layer, the thin viscous layer, is where the air molecules get stuck onto the surface of the plate and move very slowly. This layer is very thin and does not affect airflow much.

The second layer, the momentum layer, is where things get interesting. The air molecules in this layer move much faster and are less affected by the plate's surface.

Finally, the turbulent layer is where things get chaotic. In this layer, the air molecules move in random directions and create swirls and eddies. This layer affects the overall flow of air around the plate and can increase drag, making it harder for the plate to move through the air.

Scientists use the Blasius boundary layer equations to study this phenomenon and understand the complex interactions between air and surfaces. By understanding how these layers behave, engineers can design more efficient planes and cars that can move through the air with less drag and greater speed.