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heatcapacity

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heatcapacity

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Iconic Diagrams\Mechanical\Thermal\Components

Use

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

Description

This is a general model for the heat storage in a specific material. A constant temperature distribution in the material is assumed and a constant heat capacity:

 

E = int(p.dQ) + C*T0;

p.T = E/C;

 

T0 is the initial temperature of the material, E the internal energy {J} and C the thermal capacity {J/K}. Because any number of connections can be made, successive ports are named p1, p2, p3 etc. 20-sim will automatically create equations such that the resulting heat flow p.dQ is equal to the sum of the heatflows of all connected ports p1 .. pn. The temperatures of all connected ports are equal to element temperature p.T.

 

p.dQ = sum(p1.dQ, p2.dQ, ....)

p.T = p1.T = p2.T = ....

 

The thermal capacity can be calculated with the specific heat capacity cp and material mass m:

 

C = cp*m;

 

Typical values for cp are:

 

water

granite

glass

aluminium

concrete

copper

silver

iron / steel

wood

air (50 °C)

4186

790

840

900

840?

387

235

452

1674

1046

Interface

Ports

Description

p[any]

Any number of connections can be made (pseudothermal).

Causality

 

preferred temperature out

An torque out causality results in a derivative constitutive equation.

Variables

 

E

internal energy [J]

Parameters

 

C

T0

thermal capacity [J/K]

initial temperature [K]