Thursday 6/18PHYS 2010

Nathalie HoffmannUniversity of Utah

Gauge Pressure

• is the absolute pressure

• Gauge pressure shows how much the pressure exceeds atmospheric pressure/absolute pressure

Archimedes’ Principle

• The buoyant force on an object immersed in a fluid is equal to the weight of the fluid that the object displaces.

Volume Flow Rate (Q)

• Equation of Continuity:

•

• (flow rate gives the volume of fluid passing a certain point in a given time interval)

Steady vs. Unsteady Flow

• Steady flow: the flow pattern at any given point does not change with time, at any given point the flow velocity remains constant with time; does not mean the flow velocity is constant everywhere

• Unsteady flow: the flow velocity at a given point can change with time

Laminar vs. Turbulent Flow

• Laminar flow: each bit of fluid follows a path called a streamline, which do not cross

• Turbulent flow: no streamlines, adjacent bits of fluid can follow very different paths

Viscosity

• Viscosity is an intrinsic resistance to flow. Because adjacent parts of a fluid move at different velocities, the parts rub and exert frictional forces on each other.

Bernoulli’s Principle

• In a moving fluid, the pressure is low where the fluid is moving rapidly

• Assumptions: steady, laminar flow

Bernoulli’s Principle

• In a moving fluid, the pressure is low where the fluid is moving rapidly

• Assumptions: steady, laminar flow