Test 1 Flashcards
Fluid Mechanics
the study of the behavior of a gas or liquid that is either at rest or in motion
cohesive
nonwetting liquids, such as mercury, have a greater force of ______ to their contacting surface than the liquid’s adhesive force
Ideal Gas Law
The __________ relates the absolute pressure of the gas to its density and absolute temperature
Kinematic viscosity
a ratio of the fluid’s viscosity to its density
Specific gravity
the ratio of either a liquid’s density or its specific weight to that of water
density
mass per unit volume
specific weight
weight per unit volume
adhesion
wetting liquids, such as water, have a greater force of _______ to their contacting surface than the liquid’s cohesive force
Bulk modulus
measure of a fluid’s resistance to compression
viscosity
measure of a fluid’s resistance to shear
above
the body will be stable if its metacenter is located ______ its center of gravity
pressure
normal force acting per unit area
buoyant force
the _______ acting on a body immersed in a fluid is equal to the weight of fluid displaced by the body
horizontal
in a static fluid, the pressure is constant at points that lie in the same ______ plane
paraboloid
if a container has a constant rotation about a fixed axis, the liquid surface will form a forced vortex having the shape of a __________
Absolute Pressure
Pgage + Patm
Barometer
used to measure atmospheric pressure
incompressible
if the fluid is _______, then the pressure depends on the specific weight of the fluid, and it increases linearly with depth
pressure head
the ________ indicates the height of a column of liquid that produces the gage pressure
stable
regarding stability, the floating body is ________ when the center of gravity is below its center of buoyancy
convective
the _______ acceleration accounts for its spatial change, from the point where the particle enters a control surface, to the point where it exits another surface.
laminar
flow that occurs when the fluid flows in thin layers so that the fluid particles follow smooth paths
streamline
curve that indicates the direction of the velocity of particles located on it at a particular instant of time
surroundings
a system is a specific quantity of fluid that is set apart from the fluid particles outside this region, which is called the _______.
steady
this flow occurs when the flow does not change with time
local
this acceleration accounts for the time rate of change in velocity within the control volume
turbulent
this flow is very erratic, causing mixing of the fluid particles
uniform
this flow occurs when the flow does not change with location
streakline
this is formed by a succession of marked particles that all come from the same point of origin.
eulerian
this description considers a specific region (or control volume) in the flow, and it measures the motion, or a fluid property, of all the particles that pass through this region.
continuity
this equation is based on the conservation of mass, which requires that the mass of a fluid system remain constant with respect to time
extensive
fluid properties that depend upon mass
steady
this type of flow occurs when the control volume is attached to a body moving with constant velocity
positive
vectors directed outward from a control surface are _______
Mass flow
this depends on the density of the fluid and on the velocity profile passing through the area
intensive
fluid properties that are independent of mass
lagrangian
this description is used to describe the motion of fluid particles within a system of particles
eulerian
this description uses a fixed, moving, or deformable control volume to describe the motion of a system of particles that enter and exit its open control surfaces
volumetric flow
the ______ or discharge through a planar area is determined by finding the velocity of the flow perpendicular to the area
reynolds transport theorem
using the ______, we can relate the time rate of change of a fluid property for a system of particles, to its time rate of change as measured from a control volume.
Pitot
________ tubes can be used to measure the velocity of a liquid in an open channel
gravitational
for an inviscid fluid, the steady flow of a particle along a streamline is caused by pressure and _______ forces.
energy
when the fluid is viscous and/or energy is added to or removed from the fluid, the ______ equation should be used and is based on the first law of thermodynamics
Piezometer
to measure the velocity of a liquid in a closed conduit, it is necessary to use a pitot tube along with a _______, which measures the static pressure in the liquid
zero
when applying the bernoulli equation, the velocity is _______ at a stagnation point and can be assumed to be _______ at the top surface of a large reservoir
power
rate of doing shaft work
hydraulic grade line
plot of the hydraulic head
zero
when applying the bernoulli equation, the points at atmospheric openings have ______ gage pressure
energy grade line
a plot of the total head is called the _______, which will always be a constant horizontal line, provided there are no friction losses or pumps or turbines
betz’s law
a wind turbine can extract a max of 59.3% of the total power of the wind
linear and angular momentum
the ______ equations are often used to determine resultant forces and couple moments that a body or surface exerts on a fluid in order to change the fluid’s direction
turbojet or turbofan
a _______ engine is used mainly for the propulsion of the aircraft
wind turbine
a _______ decreases the linear momenum of the flow and therby remove energy from it
propeller
a ______ acts as a screw, which causes the linear momentum of the fluid to increase as it flows toward, through, then past blades
