digplanet beta 1: Athena
Share digplanet:

Agriculture

Applied sciences

Arts

Belief

Chronology

Culture

Education

Environment

Geography

Health

History

Humanities

Language

Law

Life

Mathematics

Nature

People

Politics

Science

Society

Technology

Angle of incidence

Angle of incidence is a measure of deviation of something from "straight on", for example:

## Optics

In geometric optics, the angle of incidence is the angle between a ray incident on a surface and the line perpendicular to the surface at the point of incidence, called the normal. The ray can be formed by any wave: optical, acoustic, microwave, X-ray and so on. In the figure above, the red line representing a ray makes an angle θ with the normal (dotted line). The angle of incidence at which light is first totally internally reflected is known as the critical angle. The angle of reflection and angle of refraction are other angles related to beams.

Refraction of light at the interface between two media.

### Grazing angle

When dealing with a beam that is nearly parallel to a surface, it is sometimes more useful to refer to the angle between the beam and the surface, rather than that between the beam and the surface normal, in other words 90° minus the angle of incidence. This angle is called a glancing angle or grazing angle. Incidence at small grazing angle is called "grazing incidence".

Grazing incidence diffraction is used in X-ray spectroscopy and atom optics, where significant reflection can be achieved only at small values of the grazing angle. Ridged mirrors are designed for reflection of atoms coming at small grazing angle. This angle is usually measured in milliradians.

Determining the grazing angle with respect to a planar surface is trivial, but the computation for almost any other surface is significantly more difficult. The exact solution for a sphere (which has important applications in astronomy and computer graphics) was an open problem for nearly 50 years until a closed-form result was derived by mathematicians Allen R Miller and Emanuel Vegh in 1991.[1]

## Angle of incidence of fixed-wing aircraft

Angle of incidence of an airplane wing on an airplane.

On fixed-wing aircraft, the angle of incidence (sometimes referred to as the mounting angle[2]) is the angle between the chord line of the wing where the wing is mounted to the fuselage, and a reference axis along the fuselage (often the direction of minimum drag, or where applicable, the longitudinal axis). The angle of incidence is fixed in the design of the aircraft, and with rare exceptions, cannot be varied in flight.

The term can also be applied to horizontal surfaces in general (such as canards or horizontal stabilizers) for the angle they make relative the longitudinal axis of the fuselage.

The figure to the right shows a side view of an airplane. The extended chord line of the wing root (red line) makes an angle with the longitudinal axis (roll axis) of the aircraft (blue line). Wings are typically mounted at a small positive angle of incidence, to allow the fuselage to be have a low angle with the airflow in cruising flight. Angles of incidence of about 6° are common on most general aviation designs.

Other terms for angle of incidence in this context are rigging angle and rigger's angle of incidence. It should not be confused with the angle of attack, which is the angle the wing chord presents to the airflow in flight. Note that some ambiguity in this terminology exists, as some engineering texts that focus solely on the study of airfoils and their medium may use either term when referring to angle of attack. The use of the term "angle of incidence" to refer to the angle of attack occurs chiefly in British usage.[3]

## Notes

1. ^ Allen R Miller and Emanuel Vegh (1993). "Exact Result for the Grazing Angle of Specular Reflection from a Sphere". SIAM Review 35: 472–480. doi:10.1137/1035091.
2. ^ Phillips, Warren F. (2010). Mechanics of Flight (2nd ed.). Wiley & Sons. ISBN 978-0-470-53975-0.
3. ^ Kermode, A.C. (1972), Mechanics of Flight, Chapter 3, 8th edition, Pitman Publishing, London. ISBN 0-273-31623-0
 14849 videos foundNext >
 GCSE Science Revision - Angle of IncidenceHow does light travel? How is it reflected? This video is for KS3 and KS4 Science revision. Angles of Incidence and Refraction PB2411For more great Online Tutoring Resources, visit us: http://www.primeonlinetutor.com/ Thrust angle and incidence explainedThis is a commentary on thrust angle and wing incidence and how they each affect flight performance. Very useful info for flying wings and plank style wings.... Collapse Under The Empire - Angle Of IncidenceArtist : Collapse Under The Empire Album : Find A Place To Be Safe (2009) light refraction in a glass air surface, varying incidence angleNotice that in the first refraction (from air to glass) light does not change direction (normal incidence). Light propagating in glass reaches a plane surfac... Activity K4a measuring angle of incidence and angle of reflection Calculation of angle of incidence using Snell's LawExample solution for an angle of incidence problem based on Snell's Law. Try the practice set at http://scienceprimer.com/angle-incidence-angle-refraction-pr... Physics 7.3.3.1 Identifying incident ray, reflected ray, angle of incidence, angle of reflection.https://www.braingenie.com/skills/105762/ light refraction in a air glass surface, varying incidence angleLight propagating in air reaches a plane surface separating air from glass. A fraction of light reflects back and the remaining fraction refracts to glass. A... The Echelon Effect - Angle Of IncidenceAlbum : Fracture And Fragments EP (2010)
 14849 videos foundNext >
 16 news items
 SPIE Newsroom Imager locates toxic liquids at stand-off distances SPIE Newsroom Wed, 15 May 2013 12:20:13 -0700 We have assessed the performance of the NCI system as a function of its angle of incidence. This informs us about the system's performance in a configuration representative of a realistic situation. We applied 10μl of thiodiglycol (TDG, a CWA simulant ... Artists' Gallery in Frederick hosts still-life exhibit focused on light ... Gazette.Net: Maryland Community News Online Fri, 03 May 2013 10:54:34 -0700 “Double Orange” is one of 20 oil-on-canvas paintings by Rockville artist Marie Riccio's in her latest exhibit, “Angle of Incidence,” running through May 26 at the Artists' Gallery in Frederick. “Double Orange” is one of 20 oil-on-canvas paintings by ... Synopsis: Round and Round in Circles Physics Thu, 09 May 2013 07:29:00 -0700 Near a wall, however, the particles were seen to either bounce or surf along in one direction, depending on their angle of incidence. The experimental observations can be understood by considering the viscous forces the fluid exerts on the particles ... Washington Times Global warming quiz: Do you know or think you know? Washington Times Thu, 25 Apr 2013 06:21:00 -0700 Which of of the following are the top two (2) factors in determining how much the earth's surface will be heated? a. concentration of greenhouse gases; b. angle of incidence of incoming solar radiation; c. ozone layer; d. albedo (amount of reflectivity ... The Aviation Herald Ryanair B738 at Seville on Oct 27th 2010, passenger blown over The Aviation Herald Thu, 18 Apr 2013 06:00:52 -0700 This was because the angle of incidence of the jet blast changed as the aircraft turned to leave the parking stand, allowing the jet blast to strike the passenger even though she was standing behind the jet blast barrier. EI-EBR was preparing for ... Good Design Award for nora systems specifinder.com (press release) Thu, 09 May 2013 06:32:44 -0700 The granite particles sprinkled in the matt rubber reflect light in all its facets, creating ever-changing effects on the floor depending upon the angle of incidence. The prize-winning products lend any room an exclusive atmosphere. All News from nora ... Blast from engine injured Ryanair passengers while waiting to board Irish Independent Fri, 19 Apr 2013 21:06:57 -0700 "The airline did not consider the fact that the angle of incidence of the jet blast from a turning aircraft could affect passengers or persons who, though behind the barrier, might be too close to the end of the barrier," said the CIAIAC in its report ... U.S. Patents Awarded to Inventors in Nebraska (May 10) - Targeted News Service Targeted News Service (subscription) Fri, 10 May 2013 11:50:03 -0700 ... functional combination with an alignment system (AS), and methodology of enabling calibration and very fast, (eg. seconds), sample height, angle-of-incidence and plane-of-incidence adjustments, with application in mapping ellipsometer or the like ...
 Limit to books that you can completely read online Include partial books (book previews) .gsc-branding { display:block; }

Oops, we seem to be having trouble contacting Twitter

# Talk About Angle of incidence

You can talk about Angle of incidence with people all over the world in our discussions.