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Predefined Constants

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Predefined Constants

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Some constants in 20-sim have a predefined value. These constants do not have to be declared in the constants section of a model. You can add your own predefined constants in the file Constants.ini in the 20-sim bin-directory.

 

Standard

 

pi

3.1415926535897932384626433832795

exp1

2.71828182845904523536028747135266

twopi

6.28318530717958647692528676655901

sqrt2

1.41421356237309504880168872420969

log2

0.6931471805599453094172321214581766

 

Physics

 

 

g_n

9.80665 {m/s2}

Standard acceleration of gravity

G

66.7259e-12 {N.m2/kg2}

Newtonian constant of gravitation

c_0

299.792458e6 {m/s}

Speed of light (vacuum)

mu_0

1.2566370614359172953850573533118e-6 {H/m}

Permeability (vacuum)

epsilon_0

8.854188e-12 {F/m}

Permittivity (vacuum)

h

6.6260755e-34 {J.s}

Planck constant

m_p

2.17671e-08 {kg}

Planck mass

l_p

1.61605e-35 {m}

Planck length

t_p

5.39056e-44 {s}

Planck time

e

1.60217733e-19 {C}

Elementary charge

R_H

25812.8056 {Ohm}

Quantized Hall resistance

mu_B

9.2740154e-24 {J/T}

Bohr magneton

mu_N

5.0507866e-27 {J/T}

Nuclear magneton

Ry

10973731.534 {1/m}

Rydberg constant

a_0

5.29177249e-11 {m}

Bohr radius

N_A

6.0221367e+23 {1/mol}

Avogadro constant

m_u

1.6605402e-27 {kg}

Atomic mass constant

F

96485.309 {C/mol}

Faraday constant

k

1.380658e-23 {J/K}

Boltzmann constant

sigma

5.67051e-08 {W/m2.K4}

Stefan-Boltzmann constant

b

0.002897756 {m.K}

Wien constant

R

8.31451 {J/mol.K}

Molar gas constant

V_m

0.0224141 {m3/mol}

Molar volume (ideal gas)

n_0

2.686763e+25 {1/m3}

Loschmidt constant

 

m_e

9.1093897e-31 {kg}

Electron mass

m_p

1.6726231e-27 {kg}

Proton mass

m_n

1.6749286e-27 {kg}

Neutron mass

 

Conversion Constants

 

 

eV

1.60217733e-19 {J};

Electron volt

u

1.6605402e-27 {kg}

Atomic mass unit

atm

101325 {Pa}

Standard atmosphere

deg

0.0174532925199432957692369076848861 {rad}

Angular degree