Fluid Mechanics

Fluid Statics: Study of fluids at rest in equilibrium situations.

Fluid Dynamics: Study of fluids in motion,

Fluids is any substances that is free flowing which included liquids and gases. It is a non-rigid body.

Density: Mass per unit volume.

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Pressure: Force per unit area

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PASCAL'S LAW: Pressure applied to an enclosed fluid is transmitted undiminished to every part of the fluid.

Absolute pressure: Total pressure in the fluid

Gauge Pressure: Difference between absolute temperature and atmospheric pressure

Hydrostatics Equilibrium: Net force on the fluid is zero. It has equal pressure on opposite direction. Pressure difference gives rise to a net force.

Pressure in a fluid at rest: The pressure difference between points 1 and 2 in a static fluid of uniform density is proportional to the difference between elevation y1 and y2.

image This eqn shows when y increase, p decrease

If the pressure is at rest at the surface of incompressible liquid at rest is P0, then the pressure at depth h is greater by an amount ρhg.

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SHAPE of container does not matter.

Buoyancy

ARCHIMEDE'S PRINCIPLE: When a body is immersed in a fluid, the fluid exerts an upward buoyant force on the body equal to the weight of the fluid that body displaces.

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Surface Tension: The surface of a liquid behaves like a membrane under tension. It arises because the molecules of the liquid exert attractive forces on each other.

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Ideal fluid - fluid that is incompressible (density cannot change) and has no internal friction (viscosity)

Continuity Equation - Mass of moving fluid doesn't change as it flows

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Steady flow - Overall flow pattern does not change with time

Streamline - Curve whose tangent at any point is in the direction of the fluid velocity at that point

Flow tube - tube formed by flow lines passing through the edge of an imaginary element of area.

Flow line - path of an individual particle in a moving fluid

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