Enae 311 Vocab & Concepts

Front 1

What is a fluid?

Back 1

A substance that tends to flow or conform the outlines of its container, and sometimes alters its shape in response to a force. (Gases and liquids)

Front 2

Aerodynamics

Back 2

Study of the motion of air and other gaseous fluids, and the forces acting on bodies in motion relative to those fluids

Front 3

Airfoil

Back 3

A body designed to provide a desired reaction force/moment when in motion relative to the surrounding air.

Front 4

Important attributes of an airfoil

Back 4

Span, chord, angle of attack, camber, shape (NACA), leading edge, trailing edge,

Front 5

Forces created by airfoil and directions they act. How do they arise?

Back 5

Normal (perpendicular to chord)

Axial (Parallel to chord)

Lift (perpendicular to relative wind)

Drag (Parallel to relative wind)

Pressure and shear stress distributions over the bodies surface

Front 6

How is airfoil performance measured and reported?

Back 6

Wind tunnel testing. Reported through angle of attack vs coefficient graphs

Front 7

Where are airfoil forces assumed to act?

Back 7

Center of pressure

Front 8

What does the Reynolds Transport Theorem do?

Back 8

Relates derivatives in the Lagrangian frame to derivatives in the Eulerian frame.

Front 9

Center of pressure

Back 9

Where all aerodynamic forces are assumed to act

Front 10

Dimensional Analysis

Back 10

Analytical method that allows us to identify the fundamental parameters that govern a relatively complex physical process

Front 11

Buckingham PI Theorem

Back 11

A method for reducing a number of dimensional variables describing a physical process to a smaller number of dimensionless groups

Front 12

PI groups

Back 12

If there are N variables in a problem and these variables contain K primary dimensions (for example M, L, T) the equation relating all the variables will have (N-K) dimensionless groups. These groups are the pi groups

Front 13

How does one determine pi groups?

Back 13

Choose K repeating variables. (K being # of fundamental dimensions). Make a product of those with remaining physical variables. Set up system of equations and determine exponents on repeating variables.

Front 14

Flow Similarity

Back 14

Flows that are both Geometrically similar and Dynamically similar

Front 15

Geometric Similarity

Back 15

Model and actual object have the same shape. (One is a scaled model of the other)

Front 16

Dynamic Similarity

Back 16

1. Dimensionless similarity parameters are the same for both.

2. Streamline patterns Geometrically similar

Front 17

Streamline

Back 17

A line tension to the local velocity everywhere

Front 18

Pathline

Back 18

Trajectory of an individual particle

Front 19

Streakline

Back 19

Set of fluid elements that have passed through a fixed point in space

Front 20

Streamtube

Back 20

Set of streamlines that have passed through a closed curve in space.

Front 21

When are streamlines, path lines, and streaklines all the same?

Back 21

When the flow is steady

Front 22

Mass flux

Back 22

Mass flow rate per unit area

Front 23

Stokes Theorem

Back 23

Relates integrals on closed contour to projection of vorticity on the area within contour

Front 24

Gauss's Theorem

Back 24

Relates the flux through a volumes surface to the r.o.c of velocity within volume