Fluid Mechanics Flashcards
branch of physics dealing with the action of fluid at rest or in motion, and with applications and devices in engineering using fluids
fluid mechanics
2 major areas of fluid mechanics
- fluid statics
- fluid dynamics
deals with fluids at rest
fluid statics
concerns with fluids in motion
fluid dynamics
applied to the flow of liquids or to low-velocity gas flows where gas can be considered essentially incompressible
hydrodynamics
concerned with the behavior of liquids at rest
hydrostatics
motion of gases
aerodynamics
the ff. falls under fluid statics
- pressure (Pascal’s principle)
- density
- buoyancy (Archimedes’ Principle)
- surface tension
- capillary action
the ff. falls under fluid dynamics
- types of fluid flow
- flow rate and equation of continuity
- bernoulli’s equation
- viscous fluid flow
ratio between the mass of the substance and its volume
density
ability of an object to regain its original form after the deforming force has been removed
elasticity
force that allow molecules to come together and create a bigger object
cohesive force
objects with more cohesive force are more ____
elastic
“the amount of distortion is directly proportional to the distorting force”
hooke’s law
quantity that describes the magnitude of the force causing the deformation of an object per unit area
stress
3 forms of stresses:
- tensile
- compressive
- shear
ratio of the magnitude of the force and the cross sectional area over which the force is acting on
tensile stress
when objects are pressed or pushed together
compressive stress
equal but opposite force are applied across an object
shear stress
quantitative description of the resulting deformation due to the applied force
strain
strain is defined as the ratio of the ____ in length of the object to the ____ length of the object
- change
- original
found that “for the small value of tensile stress and tensile strain, their ratio was constant for a given object”.
thomas young
force per unit area
pressure
pressure at a given level
absolute pressure
“the pressure applied to an enclosed fluid is transmitted equally in all directions and to all parts of the enclosing vessel”
pascal’s principle
“it states that the body immersed in a liquid is buoyed up by a force equal to the weight of the displaced fluid”
archimedes’ principle
“when the speed of the fluid increases, the pressure in the fluid decreases”
bernoulli’s principle
“for vessels having varied cross sectional area, flow rate in must equal flow rate out”
equation of continuity
volume of water that passes a section in a unit of time
flow rate
property of fluids that tends to prevent it from flowing when subjected to an applied force
viscosity
____ viscosity fluids resist flow
high
____ viscosity fluids flow easily
low