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Chapter 18 Dynamic Fluid

When a fluid is flowing, the pressure in the fluid comes not only from external force but also from the motion. Therefore, we need to make distinction between the static pressure we studied in the chapter on static fluid and the dynamic pressure we will study here.

Fluid dynamics provides us with fundamental explanations for a variety of physical phenomena, for instance, the flow of water in river and water pipes, wind around the wings of air planes, the flow of blood in the body, just to name a few. Fluid dynamics of water is called hydrodynamics.

Even with such a wide variety of fluid situations, there are basically two types of fluid flow, called, laminar flow and turbulent flow. As illustrated in the figure of flow of smoke, in the laminar (meaning layered) flow or stream, the fluid moves smoothly in layers with each particle moving in a smooth streamline. In the turbulent flow, we find vortices, swirls and chaotic behavior.