Download presentation
Presentation is loading. Please wait.
Published byMarian Phillips Modified over 9 years ago
1
Fluid Mechanics in Aeronautics and Astronautics Marc Williams School of Aeronautics and Astronautics
2
Aeronautics = Airplanes
3
Astronautics = Spacecraft
4
Parts of Aero & Astro Aerodynamics Design Dynamics & Control Structures Propulsion
6
Three forces from fluids LIFT - Force perpendicular to flight direction The Air pushes the airplane “up” DRAG - Force opposite the flight direction The Air pushes the airplane “back” THRUST - Force in the flight direction Internal pressure inside the engine pushes the aircraft/rocket forward
7
LIFT Newton say : The air pushes the airplane up So The airplane pushes the air down
8
Cessna Citation
9
Boeing 777
10
Boeing 757
11
DRAG The air sticks to the airplane, pushing it back (Viscosity== Friction drag) The airplane imparts kinetic energy to the air behind it…. This energy comes from the engines, And shows up as a drag (Induced Drag, or Drag due to Lift)
12
Flight Regimes – A Vocabulary 0 0 1.0 2.0 3.0 6.0 Mach Number – M Altitude (1000 ft.) 100 80 60 40 20 Subsonic Supersonic Hypersonic Structural Limit (Dynamic pressure and heating) Aerodynamic Limit Transonic V = flight speed a = speed of sound M = V / a
13
Wing Loading (N/m 2 ) All the Worlds Flyers Flyers meeting MAV requirements abound in nature Flyers with most remarkable performance leverage unsteady aerodynamics Flapping provides access to game-changing aerodynamic mechanisms for meeting MAV requirements Conventional Aircraft (Steady) Large Birds (Quasi-steady) Small Birds (Transition) Insects/Hummingbirds (Unsteady) Cruising Speed (m/s) Weight (N)
14
Micro Air Vehicles (MAVs) Unmanned aerial systems becoming for missions too dull, dirty, dangerous, or difficult for pilots – Persistent ISR – Chemical/biological sensing – “Over the hill”/“Around the corner” scouting Operation space is changing – Urban canyons – Building interiors – Subterranean caverns/bunkers MAVs are new class of vehicle to fill new operational roles Images from wikipedia.org, defense-update.com, delta.tudelft.nl
15
DYNAMICS AND CONTROL http://www.grc.nasa.gov/WWW/K-12/airplane/alr.html
16
Mach Number Effects Mach Number = Speed / Speed of Sound Speed of Sound = 340 m/s = 770 mph Mach squared = Kinetic Energy / Thermal Energy
17
An F/A-18 Hornet at transonic speedF/A-18 Hornettransonic
18
F4 phantom ii breaking the sound barrier
20
Mars Exploration RoverMars Exploration Rover (MER) aeroshell, artistic rendition
21
Thrust Thrust is produced by throwing something opposite to the direction you want to go (Newton again) You can throw air You can throw hot exhaust gases You can throw rocks… but fluids are easier to work with
22
Air Thrower
23
http://www.youtube.com/watch?v=nSQzvimD3cc Turbofan Engine This throws air and hot exhaust gases
24
Turbofan Flowpath
25
Tomahawk Cruise Missile
26
Mi-24 Hind Military Aviation Helicopter Air Thrower
27
Joint Strike Fighter- Marine Version Lift Fan Another Air Thrower
28
OSPREY- Tilt Rotor And another… but you get to change the throw direction
29
Rockets – Pure Hot Gas Throwers
30
How a Rocket Produces Thrust
31
ROCKETS BIG (SSME)
32
A micro-thruster array measuring one-quarter the size of a penny, designed by a TRW-led team for use on micro-, nano- and pico-satellites, has successfully demonstrated its functionality in a live fire test aboard a Scorpius sub-orbital sounding rocket. Individual micro-electromechanical system (MEMS) thrusters, each a poppy seed-sized cell fueled with lead styphnate propellant, fired more than 20 times at 1-second Intervals during the test staged at the White Sands Missile Range. Each thruster delivered 10(-4) Newton seconds of impulse. ROCKETS: SMALL
33
Sidewinder Air to Air supersonic missile
35
THE END Have a great summer
37
Dynamic Stall on an Airfoil
38
Boeing 757
39
Vortex break-up on a delta wing at high incidence
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.