Fluids II Test 2 Flashcards
At a point (x,y) is the net circulation per unit area around the point.
Vorticity
relates the pressure and gravitational forces acting on a differential fluid particle of an ideal fluid to its acceleration
Euler’s equations of motion
of a fluid element is defined by the average angular velocities of its two sides
rotation
is defined by the rate of change in shear strain, or the rate at which 90 degree angle between adjacent sides of the fluid element will change
angular distortion
The stream function psi(x,y) or the potential function phi(x,y) for a given flow, which satisfies both the continuity and the irrotational flow conditions, can be determined by integrating ______
Laplace’s differential equation
_______ can be applied between any two points (x1,y1) and (x2,y2) that are not necessarily located on the same streamline, provided the fluid is ideal and the steady flow is irrotational, that is w = 0.
Bernoulli equation
_______ satisfies the conditions of only irrotational flow
potential function
is a measure of the net flow around a boundary
circulation
the rate of _____ of a fluid element is defined by the velocity field, V = V(x,y,z,t)
translation
_____ is the equation that represents all the equations of the streamlines
stream function
every flow must satisfy the _____, but an ideal flow must also satisfy the conditions for incompressibility and irrotational flow
continuity condition
a set of both equipotential lines and streamlines form a ________
flow net
_____ lines are always perpendicular to streamlines at their points of intersection
equipotential
_____ or dilatation is measured by the change in volume per unit volume of the fluid element
linear distortion
since an ideal fluid is incompressible, the _____ for steady flow states that the rate of change in volume per unit volume for a fluid element must be zero
continuity equation
if w = 0, then the flow is termed _______ flow, that is, no rotation occurs.
irrotational
the rate of rotation or ______ of a fluid element of measured by the average angular velocity of two of its adjacent sides.
angular velocity
The rate at which partial(volume) per unit volume changes is called the
volumetric dilatation
_____ is the body that passes through two stagnation points and is formed when uniform flow is superimposed upon a line source and sink of equal strength, each located a distance a away from the origin
rankine oval
______ is the field of study that is now widely used to design and analyze many different types of fluid flow problems, such as those involving aircraft, pumps and turbines, heating and ventilation equipment, wind loadings on buildings, chemical processes, and biomedical implant devices, and it is even used for atmospheric weather modeling
CFD
the _______ equations together with the continuity equation, these four partial differential equations provide a means of obtaining the velocity components u, v, w, and the pressure p within the flow
navier-stokes
the responsibility of using any CFD program lies in the hands of the ______, and for that reason, he or she must ultimately be accountable for the results
operator (engineer)
when a line source and a line sink come close to one another and then combine, they form a _____
doublet
Since the body extends an infinite distance to the right, its top and bottom surfaces approach asymptotes, and so it has no closure. For this reason, it is referred to as _______
half body
regarding a uniform and free-vortex flow around a cylinder, only a downward force Fy exists perpendicular to the uniform flow, causing lift. This is known as the _____
magnus effect
the ______ method has become well established and is currently used in most CFD software
Finite Control Volume
when inertia, pressure, and gravity forces predominate within the flow along open channels, over dams and spillways, or the wave action on structures, _____ number similitude should be considered
froude
what important dimensionless number describes the flow behavior when pressure and inertia forces are dominant, as when a liquid flows through a pipe?
Euler number
What important dimensionless number describes capillary flow?
Weber number
