Aspect ratio

created by yossarian

(thing) by Film Terms (?) (print) ? (I like it!) Thu Mar 23 2000 at 17:53:54

The proportions of the frame. In 16mm and 35mm the camera photographs a slightly square image, with an aspect ratio of 1.33 to 1. Aspect Ratios are usually shorted to leave out the "- to 1," taking for granted that it will always be in relation to 1, an so "1.33 to 1" can just be called "1.33" In 35mm 1.33 is known as the Academy Aperture. In 35mm the image is usually shot with the Academy Aperture and then masked in the projector to produce a wider image: 1.85 in the U.S. and 1.66 in Europe.

Glossary of Film Terms - http://homepage.newschool.edu/~schlemoj/film_courses/glossary_of_film_terms/
reprinted with permission

(idea) by maxClimb (12.7 min) (print) ? (I like it!) Fri Mar 09 2001 at 15:40:48

In aviation - Aspect Ratio refers to the shape of the wings of an aircraft, i.e. long and skinny or short and fat.
The simplest expression of AR is span/chord, where span is the distance from wingtip to wingtip and the chord is the distance from the leading edge to the trailing edge of the wing. This works for rectangular wings such as those found on Cessnas and other small airplanes. For tapered and/or swept wings the average chord is needed. In these cases a more useful equation for AR is span^2/area.

Aspect Ratio relates to the performance of a wing, that is to say, its efficiency (at a given speed or speed range). Aerodynamic drag is the chief foe of wing efficiency, and comes in two forms: parasite drag and induced drag. The former is the result of airflow disruption by struts, wheels, fuselage, etc. Induced drag is a consequence of the production of lift. A certain amount of energy goes into moving air in ways that don't lift the aircraft; an example is the tip vortex, where air swirls from the bottom to the top of the wing at the tip. The effects of drag increase as the square of airspeed.
Induced drag varies inversely with aspect ratio, so a wing with infinite span would have zero induced drag. High performance sailplanes, with their very long and skinny wings, have ARs of 30 or higher. The Space Shuttle has an AR of maybe 1.5. Hang gliders have ARs in the 5.5 to 8.5 range.
Low aspect ratios generally work better for wings designed to produce a lot of lift at low speeds, high aspect ratios are better for higher speed applications where minimal lift (beyond supporting the aircraft) is needed. Lower AR wings are generally much more maneuverable than high AR wings as well.
Structural factors limit the attainable aspect ratio using a given material or materials, and the neccesary light weight means that very high AR wings tend to flex or curve dynamically under load, which further complicates designing for efficiency and realizing the theoretical benefits of high AR.

(idea) by spencerogden (2 y) (print) ? (I like it!) Mon Dec 03 2001 at 6:35:27

In general "aspect ratio" refers to foils, in any fluid, water or air. The ratio we are interested in is the length of the foil compared to it chord. A long skinny wing, such as found on sailplanes is said to have a high aspect ratio, whereas a fighter jet has stubby low aspect ratio wings. As a rule of thumb, the higher the aspect ratio, the more efficient the wing, i.e. the more lift it can create per unit of drag. This is due the the reduction of wing tip vorticies.

(definition) by Webster 1913 (print) Mon Mar 14 2005 at 3:04:45

Aspect ratio. (Aeronautics)

The ratio of the long to the short side of an aeroplane, aerocurve, or wing.

printable version
chaos

enhanced for 16x9 televisions	widescreen	Academy Aperture	Mongolian hordes programming
Sony WEGA	pan & scan	35 mm film	silver ratio
Germ theory	Lockheed T-33	ratio	planform area
Direct-view video technologies	Narrow Bandwidth Television Association	The Golden Ratio: Nature's Formula for Perfection	Favorite Everything quotes
CCD	Elliptical planform	Lark	cell phone programming
Hysteresis	graphics tablet	sailplane	The Bridge on the River Kwai

Y'know, if you log in, you can write something here, or contact authors directly on the site. Create a New User if you don't already have an account.

Login
Password

remember me
password reminder
register

Everything2 Help

After stirring Everything, these nodes rose to the top:
U-2 Incident
time
Welcome to the Involuntary Agnostics Association
Theodore Roosevelt
I had forgotten the bear's name, and could not find my way home to the Thousand Acre wood
Kit Kat Konspiracy
Dennis the Menace
Life of Pi
PostScript
Confession
Did Aum Shinrikyo set off a nuclear bomb in Western Australia in 1993?
Etacism
How to love someone who is mentally ill

antigravpussy
One fly amonst many	(person)
sam512
Moon Base Shackleton, 1978	(fiction)
Pavlovna
toy boy	(person)
XWiz
tear jerker	(review)
Heitah
Anarchy is Order	(idea)
jessicaj
July 26, 2008	(dream)
Berek
ABBA	(person)
devolution
k-hole	(place)
Nadine_2
The Sound Of Madness	(review)
Twin Eclipse
Conversations with God: An Uncommon Dialogue	(idea)
SwimmingMonkey
Conversations with Fo Fo- the Loneliest dog in Purgatory	(fiction)
locke baron
lynx	(thing)
Simulacron3
Reality, Dimensions and the Natural Ontology	(essay)
SubSane
Making Love to a 9-Foot Woman	(person)
Ouzo
Thoughts	(idea)

This page courtesy of The Everything Development Company