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Iconic Diagrams\Mechanical\Thermal\Components

Use

Domains: Continuous. Size: 1-D. Kind: Iconic Diagrams (Pseudothermal).

Description

This model describes the heat transfer between to bodies through radiation:

p.dQ =Gr*sigma*(p1.T^4 - p2.T^4);

where p1.T and p2.T are the temperatures of the body surfaces and sigma is the Stefan-Boltzmann constant. For simple cases, Gr may be analytically computed. The analytical equations use epsilon, the surface emissitivy of a body which is in the range 0..1. Epsilon=1, if the body absorbs all radiation (= black body). Epsilon=0, if the body reflects all radiation and does not absorb any.

Typical values for epsilon are:

Analytical Equations for Gr

Small convex object in large enclosure (e.g., a hot machine in a room):

 Gr = e*A;

where

e: Emission value of object (0..1)

A: Surface area of object where radiation heat transfer takes place

Two parallel plates:

Gr = A/(1/e1 + 1/e2 - 1);

where

e1: Emission value of plate1 (0..1)

e2: Emission value of plate2 (0..1)

A : Area of plate1 (= area of plate2)

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