lib.physics module

Module for implement physics correlation:

  • Constants don’t available in scipy.constants

  • Particle solid distributions

  • Other
lib.physics.normal(media, varianza)[source]
lib.physics.lognormal(media, varianza)[source]
lib.physics.weibull(escala, start, forma)[source]
lib.physics.cubicCardano(a, b, c, d)[source]

Implementation of Cardano formula to find all roots in a cubic equation faster than with scipy.roots

\[ax^3 + bx^2 + cx + d = 0\]

Algorithms referenced at http://www.1728.org/cubic2.htm

Parameters:
afloat

Third grade coefficient, [-]

bfloat

Second grade coefficient, [-]

cfloat

First grade coefficient, [-]

dfloat

Zero grade coefficient, [-]

Returns:
rootlist

Solution list, [-]

Examples

# (x+2)^3

>>> "%i %i %i" % (cubicCardano(1, 6, 12, 8))
'2 2 2'

# (x-2)^3

>>> "%i %i %i" % (cubicCardano(1, -6, 12, -8))
'-2 -2 -2'

>>> "%.1f %.1f %.1f" % (cubicCardano(2, -4, -22, 24))
'-3.0 1.0 4.0'

>>> "{:.4f} {:.4f} {:.4f}".format(*cubicCardano(3, -10, 14, 27))
'-1.0000 2.1667+2.0750j 2.1667-2.0750j'
lib.physics.Cunningham(l, Kn, method=0)[source]

Cunningham slip correction factor for air l: Mean free path kn: Knudsen dimensionless number method: reference procedure

0 - Jennings (1987) 1 - Allen & Raabe (1982) 2 - Fuchs (1964) 3 - Davies (1945)

lib.physics.Collision_Neufeld(T, l=2, s=2, simple=False)[source]

Calculate the collision integral using the Neufeld correlation

\[\varOmega^{(l,s)}=A/T^{B}+C/\exp\left(DT\right)+E/\exp\left(FT\right)+ G/\exp\left(HT\right)+RT^{B}\sin\left(ST^{w}-P\right)\]

A,B,C,D,E,F,G,H,R,S,W,P are constants for each collison order

Parameters:
Tfloat

Reduced temperature, [-]

l: int, optional

Collision integral first term order, default 2

sint, optional

Collision integral second term order, default 2

simpleboolean, optional

Calculate a short formulation without the last sin term

Returns:
omegafloat

Transport collision integral, [-]

References

[1] Neufeld, P.D., Janzen, A.R., Aziz, R.A.; Empirical Equations to Calculate 16 of the Transport Collision Integrals Ω for the Lennard-Jones Potential. J. Chem. Phys. 57(3) (1972) 1100-1102

References