Fluids II Test 2

Question 1

At a point (x,y) is the net circulation per unit area around the point.

Answer 1

Vorticity

Question 2

relates the pressure and gravitational forces acting on a differential fluid particle of an ideal fluid to its acceleration

Answer 2

Euler’s equations of motion

Question 3

of a fluid element is defined by the average angular velocities of its two sides

Answer 3

rotation

Question 4

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

Answer 4

angular distortion

Question 5

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 ______

Answer 5

Laplace’s differential equation

Question 6

_______ 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.

Answer 6

Bernoulli equation

Question 7

_______ satisfies the conditions of only irrotational flow

Answer 7

potential function

Question 8

is a measure of the net flow around a boundary

Answer 8

circulation

Question 9

the rate of _____ of a fluid element is defined by the velocity field, V = V(x,y,z,t)

Answer 9

translation

Question 10

_____ is the equation that represents all the equations of the streamlines

Answer 10

stream function

Question 11

every flow must satisfy the _____, but an ideal flow must also satisfy the conditions for incompressibility and irrotational flow

Answer 11

continuity condition

Question 12

a set of both equipotential lines and streamlines form a ________

Answer 12

flow net

Question 13

_____ lines are always perpendicular to streamlines at their points of intersection

Answer 13

equipotential

Question 14

_____ or dilatation is measured by the change in volume per unit volume of the fluid element

Answer 14

linear distortion

Question 15

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

Answer 15

continuity equation

Question 16

if w = 0, then the flow is termed _______ flow, that is, no rotation occurs.

Answer 16

irrotational

Question 17

the rate of rotation or ______ of a fluid element of measured by the average angular velocity of two of its adjacent sides.

Answer 17

angular velocity

Question 18

The rate at which partial(volume) per unit volume changes is called the

Answer 18

volumetric dilatation

Question 19

_____ 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

Answer 19

rankine oval

Question 20

______ 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

Answer 20

CFD

Question 21

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

Answer 21

navier-stokes

Question 22

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

Answer 22

operator (engineer)

Question 23

when a line source and a line sink come close to one another and then combine, they form a _____

Answer 23

doublet

Question 24

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 _______

Answer 24

half body

Question 25

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 _____

Answer 25

magnus effect

Question 26

the ______ method has become well established and is currently used in most CFD software

Answer 26

Finite Control Volume

Question 27

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

Answer 27

froude

Question 28

what important dimensionless number describes the flow behavior when pressure and inertia forces are dominant, as when a liquid flows through a pipe?

Answer 28

Euler number

Question 29

What important dimensionless number describes capillary flow?

Answer 29

Weber number