AE312 :: Compressible flow

Professor D. J. BodonySpring, 2014103 Talbot

1:00-1:50 p.m., MWF

Compressible fluids are everywhere

American Scientist

Video 1

Video 2

Video 3

In everyday objects...

American Scientist

In high-speed aircraft...

In aircraft gas turbine engines (AE433)...

Pratt & Whitney 6000 engine, simulated by Stanford's ASC Center

And in not-so everyday objects...

SSME SR-71

In NASA's Apollo & Orion capsules...

Apollo at “hypersonic” speed

and in even “slow” objects...

At fortissimo, J. Acoust. Soc. Am. 99 (3), March 1996

What is this course about?

Fluid dynamics of a compressible medium A compressible medium is one in which the

density can change. This leads to– steady flow where velocity ~ speed of sound (e.g.,

high-speed aircraft)– wave propagation (e.g., sound waves, shock waves)– convection driven by body forces with thermal

expansion (e.g., rising of hot air)– large scale motion of gases in presence of gravity

(e.g., the atmosphere)

AE312

AE412

What is important in this course?

1. Ability to think

What is important in this course?

1. Ability to think2. Ability to think about compressible fluids

What is important in this course?

1. Ability to think2. Ability to think about compressible fluids3. Ability to think about compressible media

a) classical structures and fluids are part of continuum mechanics

b) they both have waves, shocks, etc.

What is important in this course?

1. Ability to think2. Ability to think about compressible fluids3. Ability to think about compressible media

a) classical structures and fluids are part of continuum mechanics

b) they both have waves, shocks, etc.4. Ability to generalize ideas to other areas

1. Air traffic control uses governing equations that have their roots in compressible fluids (e.g., Hamilton-Jacobi problems).

2. “Shocks” in ATC are bad.