RADIATION IN ENCLOSURES WITH SOME SPECULARLY REFLECTING SURFACES Exchange Factor Net Radiation Method Curved Specularly Reflecting Surfaces.

Slides:



Advertisements
Similar presentations
Light and the Electromagnetic Spectrum. Light as a Wave light is a visible form of energy most of the energy that surrounds us is invisible this energy.
Advertisements

Computer Vision Radiometry. Bahadir K. Gunturk2 Radiometry Radiometry is the part of image formation concerned with the relation among the amounts of.
Waves – Topic 4 Chapters 26 Reflection & Refraction Reflection & Refraction Reflection & Refraction.
LECTURE 25 – RADIATION VIEW FACTORS. VIEW FACTORS THE EQUIVALENT FRACTION OF RADIATION FROM ONE SURFACE THAT IS INTERCEPTED BY A SECOND SURFACE ALSO CALLED.
Radiation Exchange EGR 4345 Heat Transfer. Blackbody Radiation Exchange.
The bouncing off of light as it hits a surface
Radiation: Processes and Properties Basic Principles and Definitions 1.
Radiation Heat Transfer P M V Subbarao Associate Professor Mechanical Engineering Department IIT Delhi Select a Suitable Geometry to meet the industrial.
Chapter 13 RADIATION HEAT TRANSFER
A wave front consists of all points in a wave that are in the same phase of motion. A wave front is one of many properties that light waves share with.
Chapter 32Light: Reflection and Refraction. Electromagnetic waves can have any wavelength; we have given different names to different parts of the wavelength.
Reflection Light incident upon a boundary between
AP Physics B Mrs. Wallace. Reflection Reflection occurs when light bounces off a surface. There are two types of reflection Specular reflection Off a.
Reflection of Light. When light rays hit an object, they change direction. The type of surface the light encounters determines the type of reflection.
Nature of Light. Light Light can be modeled as a wave and a particle Transverse, electromagnetic wave Photons — particles of light.
Review from last class – Complete in your notes. 1.A pinhole camera creates an image of a 37- meter-tall tree. If the image is 2.4 cm tall and inverted,
Reflection & Refraction of Light Reflection: specular (mirror) vs diffuse angle of incidence = angle of reflection Refraction: Snell’s Law n 1 sin 
Distinguish between specular and diffuse reflection of light. Apply the law of reflection for flat mirrors. Describe the nature of images formed by flat.
CH 32: geometric optics. Reflection: Reflection is the simplest method for changing the direction of light. Reflection – Light incident on a boundary.
FLAT MIRRORS Chapter 13: Section 2. Learning Targets  Describe how the angle of incidence is related to the angle of reflection  Explain how surface.
Radiation Definitions and laws Heat transfer by conduction and convection required the existence of a material medium, either a solid or a.
Laws of Radiation Heat Transfer P M V Subbarao Associate Professor Mechanical Engineering Department IIT Delhi Macro Description of highly complex Wave.
Light, Mirrors, and Lenses O 4.2 Reflection and Mirrors.
Radiation Heat Transfer
Attenuation by absorption and scattering
Sun path diagrams For practical purposes, instead of using the preceding equations, it is convenient to have the sun’s path plotted on a horizontal plane,
The Ray Model of Light. Light travels in straight lines: Laser Part 1 – Properties of Light.
THE RAY MODEL OF LIGHT Section 11.4.
AP Physics IV.C Geometric Optics. Wave Fronts and Rays.
Line Ray Beam the paths along which light energy travels a bundle of light rays.
Plane Mirrors.
Reflection and Light Flat Mirrors.
Properties of Reflective Waves Flat Mirrors. Light travels in a straight line Some light is absorbed Some light is redirected – “Reflected”
Chapter 14 - Light Electromagnetic Wave- a wave that consists of vibrating electric and magnetic fields that radiate outward from the source at the speed.
Chapter 21 RADIATION HEAT TRANSFER Copyright © 2012 The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Fundamentals of Thermal-Fluid.
11.4 The Ray Model of Light.
Introduction to Thermal Radiation and Radiation Heat Transfer.
AP Physics 2 Unit 6 Wave Motion and Geometric Optics.
Types & Laws of Reflection
Notes on Chapter 29 Reflection & Refraction
23 Light: Geometric Optics We see objects by emitted light or reflected light.
1 Teaching Innovation - Entrepreneurial - Global The Centre for Technology enabled Teaching & Learning D M I E T R, Wardha DTEL DTEL (Department for Technology.
RADIATION EXCHANGE IN AN ENCLOSURE WITH DIFFUSE-GRAY SURFACES Net radiation method Simplified zone analysis Electric network analogy Generalized zone analysis.
The incident ray and the reflected ray behave in predictable ways, which leads to the two laws of reflection: 1.The angle of incidence equals the angle.
Lesson 1.  Reflection occurs when light bounces off a surface.  Specular reflection occurs when light reflects off a shiny surface.  Diffuse reflection.
Circular wave fronts Plane wave Fronts Produced in a Ripple Tank.
AHMEDABAD INSTITUTE OF TECHNOLOGY
Light, Mirrors, and Lenses
Geometric Optics TEST: 12 April 2016.
How else do you look pretty in the morning?
Laws of reflection.
Reflection of Light Definition of Reflection Types of Reflection
The Apparent Absorptivity of the Infinite V-groove
Reflection & Refraction
Reflection and Refraction
By: Derek Anderson & Alex Walker
Learning goals We are learning the types of reflection.
Learning goals We are learning the types of reflection.
Lesson 14 Key Concepts and Notes
The law of reflection: The law of refraction: Image formation
Reflection and Light Flat Mirrors.
Flat Mirrors.
Reflection Physics Chapter 18a.
Conceptual Physics Notes on Chapter 29 Reflection & Refraction.
OPTICAL DESIGN K.F. Chan (Mr.) MEBS 6002.
10.2 How we see the image.
The Ray Model of Light Light travels in a straight line Recall
air water As light reaches the boundary between two media,
Radiation Heat Transfer
Aim: How do we explain the law of reflection?
Presentation transcript:

RADIATION IN ENCLOSURES WITH SOME SPECULARLY REFLECTING SURFACES Exchange Factor Net Radiation Method Curved Specularly Reflecting Surfaces

Scope optical roughness long wavelength (infrared): specular fashion assumptions: 1)Specular reflectivity is independent of incident angle of radiation. 2) All surfaces are gray.

A1A1 A2A2 diffuse reflector specular reflector dA 1 Exchange Factor Specular view factor Mirror-image method (Eckert & Sparrow 1965) dA 1(2) dA 1(2) : mirror image of dA 1 through A 2 A 1(2)

dA 1 A1A1 A2A2 dA 1(2) When A 2 is a perfect specular reflector : the fraction of radiation energy leaving dA 1 that strikes A 1 after one specular reflection at A 2 : specular reflector diffuse reflector When :

A 1(2) dA 1 A1A1 A2A2 diffuse reflector specular reflector dA 1(2) fraction : partial diffuse view factor

Ex A2A2 A3A3 A4A4 A1A1 A 4(3) A 2(3) A 1(3) A 1, A 2, A 4 : diffuse A 3 : specular

A 1(3) A 1(2,3) Ex A2A2 A3A3 A4A4 A1A1 A 4(3) A 2(3) A 1(2) A 3(2) A 4(2) A 4(2,3)

Reciprocity for specular surfaces A 1 black A 2 black A 3, specular A 1(3) A 2(3) isothermal enclosure since

A 2 black A 3, specular A 1(3) A 2(3) A 1 black A4A4

isothermal enclosure A 2 black A 3, specular A 1(3) A 2(3) A 1 black

Net Radiation Method enclosure with n plane surfaces d : diffuse reflecting surfaces n - d : specularly reflecting surfaces for diffuse surfaces: or for specular surfaces: irradiation

parallel plates (both specular) Ex -- T 1,  1  -- T 2,  2 

spherical vacuum bottle specular: diffuse: specular: diffuse: Ex K 0.65 cm A2A2 e = cm A1A1 368 K

Ex 9-6 1/A 2 F 23 1/A 1 F 13 1/A 1 F 12 J1J1 eb1eb1 eb2eb2 eb3eb3 q1q1 a) surface 1 : diffuse reflector 45° A3A3 A2A2 A1A1 T 3 = 750 K,  3 = 1 T 2 = 525 K,  2 = 1 T 1 = 525 K,  1 = 0.05

b) surface 1 : specular

1) direct: Curved Specularly Reflecting Surface specular tube Ex Let dX 1 dX D

2) one-reflection: 3) n reflection: dX 1 dXdX/2

Feedback: Privacy Policy Feedback
Do Not Sell My Personal Information
About project: SlidePlayer Terms of Service

© 2025 SlidePlayer.com. Inc. All rights reserved.