Package wiat :: Package TM :: Module Waveguides

Module Waveguides

Waveguides.py - Contains classes defining the transmission matrices for simple geometries and functions to generate them.

Classes

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Waveguides
Base class for waveguides

Cylinder
Class representing a cylinder

Cone
Truncated cone transmission matrix calculation class

CurvedCone
Class representing a curved cone

Jump
Class representing a diameter jump

ToneHole
This class implements the transmission matrix of tone holes References:

Functions

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PropagationConstant(f, a, air, beta)
Calculate the complex propagation constant in an acoustic waveguide

source code

CreateCylindersAndConesFromList(list)
Build a list of Cylinder or Cone from a list of tuples containing position and diameters.

source code

ConeApproximatedWithCylinders(d0, de, L, N=200)

source code

EquationApproximatedWithCones(equation, L, N=10)
Discretization in conical segments of an equation giving the radius of the waveguide as a function of its argument.

source code

Function Details

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PropagationConstant(f, a, air, beta)

source code

Calculate the complex propagation constant in an acoustic waveguide

See Allan D. Pierce p. 531-534

Parameters:

f - frequency array
a - tube radius
air - Air instance
beta - factor to take into account wall roughness

Returns:

Γ = α + 1j * ω / v_φ where α is the attenuation, ω is 2πf and v_φ is the phase velocity

CreateCylindersAndConesFromList(list)

source code

Build a list of Cylinder or Cone from a list of tuples containing position and diameters.

Example:

   >>> import wiat
   >>> FluteBody = wiat.TM.CreateCylindersAndConesFromList(
   ... [(0.,0.0188),(0.132,0.0188),(0.340,0.0152),
   ...  (0.452,0.0135),(0.583,0.0112)])
   >>> for s in FluteBody: print s
   Cylinder(d=0.0188,L=0.1320)
   Cone(d0=0.0188,de=0.0152,L=0.2080)
   Cone(d0=0.0152,de=0.0135,L=0.1120)
   Cone(d0=0.0135,de=0.0112,L=0.1310)

Parameters:

list - a list of tuples (position,diameter) where the position is the distance along the centerline of the instrument from the mouthpiece.

EquationApproximatedWithCones(equation, L, N=10)

source code

Discretization in conical segments of an equation giving the radius of the waveguide as a function of its argument.

Parameters:

equation - an equation of one argument. It will be evaluated from 0 to L.
L - the length of the waveguide.