4.1 A Close Up Look at Fluid Flow
1) Aerodynamics is an important aspect of transportation. To improve fuel efficiency, reduce drag/friction to improve speed, to improve safety, and to improve technological advances in strong, lightweight materials etc.; these are some of the dynamic aspects of travel that are important to the transportation industry.
The flow of air over the curved surface of an airplane wing creates a low pressure area above the wing. The pressure below the wing is greater than that above the wing, coupled with propulsion, this allows the airplane to rise. It is the Bernoulli principle that explains the details of liftoff.
Gliders use air currents to move.
Airflow provides the wind force to operate a sailboat.
Air brakes are used on large transport trucks and other large vehicles.
2) A substance changes its state when enough heat energy is added or taken away.
3) Evaporation and condensation are both changes of state (phases of matter). They are also the opposites of each other.
4) The opposite of evaporation is condensation
The opposite of solidification is melting.
The opposite of sublimation (solid to gas) is desublimation or deposition (gas to solid – frost on the windshield)
5) An example of sublimation is when wet clothes freeze outside on a cold, sunny day but are dry several hours later (freeze dried). Ice cubes in a tray will shrink if they are left for long periods of time. Dry Ice (solid carbon dioxide) changes directly to a gas at room temperature.
6) The kinetic molecular theory states that the particles of a solid are so close together and tightly linked by their forces of attraction that they cannot move out of their position. They vibrate. They cannot flow. They have a rigid structure.
4.2 Fluid Flow around Objects
1) Laminar Flow – the flow of air around streamlined shapes such as airplane wings and footballs; the flow of water of marine mammals; the Fraser River delta; sheets of rainwater flowing over pavement……
Turbulent Flow – the flow of water in rapids, mountain streams, rocky areas, whitewater etc.; the flow of air around buildings and other large structures; the flow of fluid in a tube or artery where restriction/constriction occurs……..
2) Car mirrors with a streamlined design improve fuel efficiency, reduce drag, reduce wind noise and can improve the car’s overall performance.
3) The blocked artery would produce more turbulent, inconsistent blood flow.
4) Scientists study airflow to improve safety; reduce wind noise; improve energy efficiency; improve performance/technology……..
Think about ways you benefit from the study of aerodynamics and fluid flow.