"""
Monopole source is a good approximation for speaker mounted on the wall
of the duct if the wavelength of sound wave is much longer than the width
of duct.
"""
from __future__ import division
import numpy as np
import duct
freq = 50
#s = duct.MonopoleSource(position=1, generator=duct.PulseGenerator(amp=1, delay=0))
s = duct.MonopoleSource(position=1,
generator=duct.SineGenerator(q=0.001, freq=freq))
duct.animate([s])
freq = 50
waveLength = duct.c0 / freq
qp = 1
primSrc = duct.MonopoleSource(position=1,
generator=duct.SineGenerator(qp, freq),
name='Primary source')
d = 0.5
L = waveLength * 3/4
k = 2*np.pi / waveLength
qs2 = -qp * np.exp(-1j*k*L) / (2j*np.sin(k*d))
qs1 = -qs2 * np.exp(-1j*k*d)
secSrc1 = duct.MonopoleSource(position=1+L,
generator=duct.SineGenerator(qs1, freq),
name='Secondary source 1')
secSrc2 = duct.MonopoleSource(position=1+L+d,
generator=duct.SineGenerator(qs2, freq),
name='Secondary source 2')
duct.animate([primSrc, secSrc1, secSrc2])
""" alternative means of generating sound """ from __future__ import division import numpy as np import duct duct.xMax = 10 freq = 50 f = 1 s = duct.DipoleSource(position=4, generator=duct.SineGenerator(f/(duct.ro0*duct.c0), freq)) #s = duct.DipoleSource(position=4, generator=duct.PulseGenerator(amp=1/(duct.ro0*duct.c0), delay=0)) duct.animate([s])
# sine waves
if 0:
freq = 50
waveLength = duct.c0 / freq
k = 2 * np.pi / waveLength
q1 = 1
#L = waveLength/2 # cancelation in both directions
L = waveLength * 5 / 8
#L = waveLength * 3/4
#L = waveLength
q2 = -q1 * np.exp(-1j * k * L) # necessary for calculation
primSrc = duct.MonopoleSource(position=1,
generator=duct.SineGenerator(q1, freq))
secSrc = duct.MonopoleSource(position=1 + L,
generator=duct.SineGenerator(q2, freq))
# pulse
else:
primSrc = duct.MonopoleSource(position=3,
generator=duct.PulseGenerator(amp=1,
delay=0))
L = 2
delay = L / duct.c0
secSrc = duct.MonopoleSource(position=3 + L,
generator=duct.PulseGenerator(amp=-1,
delay=delay))
duct.animate([primSrc, secSrc])
Primary source radiates two rectangular pulses with opposite amplitude.
The result is ping pong pictured in figure 5.15 in the book.
"""
from __future__ import division
import numpy as np
import duct
duct.xMax = 10
L = 3
d = 1
amp = 0.01
primSrc_pulse1 = duct.MonopoleSource(position=1,
generator=duct.PulseGenerator(amp),
name='Primary source, 1st pulse')
primSrc_pulse2 = duct.MonopoleSource(position=1,
generator=duct.PulseGenerator(
-amp, 2 * d / duct.c0),
name='Primary source, 2st pulse')
secSrc1 = duct.MonopoleSource(position=1 + L,
generator=duct.PulseGenerator(
amp, (L + 2 * d) / duct.c0),
name='Secondary source 1')
secSrc2 = duct.MonopoleSource(position=1 + L + d,
generator=duct.PulseGenerator(
-amp, (L + d) / duct.c0),
name='Secondary source 2')
duct.animate([primSrc_pulse1, primSrc_pulse2, secSrc1, secSrc2])
from __future__ import division
import numpy as np
import duct
duct.xMax = 10
freq = 50
waveLength = duct.c0 / freq
k = 2*np.pi / waveLength
qp = 0.01
primSrc = duct.MonopoleSource(position=1, generator=duct.SineGenerator(qp, freq),
name='Primary source')
L = waveLength * 3/4
f = - duct.ro0 * duct.c0 * qp/2 * np.exp(-1j*k*L)
qs = -qp/2 * np.exp(-1j*k*L)
secMonoSrc = duct.MonopoleSource(position=1+L, generator=duct.SineGenerator(qs, freq),
name='Secondary monopole source')
secDipoleSrc = duct.DipoleSource(position=1+L, generator=duct.SineGenerator(f/(duct.ro0*duct.c0), freq),
name='Secondary dipole source')
duct.animate([primSrc, secMonoSrc, secDipoleSrc])
and secondary on the left at x=0.
"""
from __future__ import division
import numpy as np
import duct
duct.xMax = 5
freq = 50
waveLength = duct.c0 / freq
k = 2 * np.pi / waveLength
L = 2
ampPrim = 0.01
sp = duct.MonopoleSource(position=L,
generator=duct.PulseGenerator(ampPrim, 0),
name='Primary source')
# Amplitude and delay to ensure no reflected sound.
# Compared to equation 5.15.4 in Nelson&Elliott we added factor 1/2,
# because in our case the duct is opened on primary source side.
ampSec = -ampPrim / 2
delay = L / duct.c0
ss = duct.MonopoleSource(position=0,
generator=duct.PulseGenerator(ampSec, delay),
name='Secondary source')
duct.animate([sp, ss], reflect=True)
from __future__ import division
import numpy as np
import duct
duct.xMax = 10
freq = 50
waveLength = duct.c0 / freq
k = 2 * np.pi / waveLength
qp = 0.01
primSrc = duct.MonopoleSource(position=1,
generator=duct.SineGenerator(qp, freq),
name='Primary source')
L = waveLength * 3 / 4
f = -duct.ro0 * duct.c0 * qp / 2 * np.exp(-1j * k * L)
qs = -qp / 2 * np.exp(-1j * k * L)
secMonoSrc = duct.MonopoleSource(position=1 + L,
generator=duct.SineGenerator(qs, freq),
name='Secondary monopole source')
secDipoleSrc = duct.DipoleSource(position=1 + L,
generator=duct.SineGenerator(
f / (duct.ro0 * duct.c0), freq),
name='Secondary dipole source')
duct.animate([primSrc, secMonoSrc, secDipoleSrc])
import numpy as np
import duct
duct.xMax = 10
freq = 50
waveLength = duct.c0 / freq
k = 2 * np.pi / waveLength
D = 1
L = 2
# at D=0 and kL=pi/2+n*pi we will have truble - check the amplitude of sec source
#D = 0.01
#L = np.pi/(2*k)
qp = 0.01
primSrc = duct.MonopoleSource(position=D,
generator=duct.SineGenerator(qp, freq),
name='Primary source')
# equation 5.11.4 for R=1
qs = -qp * (np.exp(1j * k * D) + np.exp(-1j * k * D)) / (np.exp(1j * k * L) +
np.exp(-1j * k * L))
secSrc = duct.MonopoleSource(position=L,
generator=duct.SineGenerator(qs, freq),
name='Secondary source')
duct.animate([primSrc, secSrc], reflect=True)
duct.xMax = 10
freq = 50
waveLength = duct.c0 / freq
k = 2*np.pi / waveLength
D=1
L=2
# at D=0 and kL=pi/2+n*pi we will have truble - check the amplitude of sec source
#D = 0.01
#L = np.pi/(2*k)
qp = 0.01
primSrc = duct.MonopoleSource(position=D, generator=duct.SineGenerator(qp, freq),
name='Primary source')
# equation 5.11.4 for R=1
qs = -qp*(np.exp(1j*k*D) + np.exp(-1j*k*D)) / (np.exp(1j*k*L) + np.exp(-1j*k*L))
secSrc = duct.MonopoleSource(position=L, generator=duct.SineGenerator(qs, freq),
name='Secondary source')
duct.animate([primSrc, secSrc], reflect=True)
import duct
duct.xMax = 5
freq = 50
waveLength = duct.c0 / freq
k = 2*np.pi / waveLength
L = 2
ampPrim = 0.01
sp = duct.MonopoleSource(position=L, generator=duct.PulseGenerator(ampPrim, 0),
name='Primary source')
# Amplitude and delay to ensure no reflected sound.
# Compared to equation 5.15.4 in Nelson&Elliott we added factor 1/2,
# because in our case the duct is opened on primary source side.
ampSec = -ampPrim/2
delay = L/duct.c0
ss = duct.MonopoleSource(position=0, generator=duct.PulseGenerator(ampSec, delay),
name='Secondary source')
duct.animate([sp, ss], reflect=True)
from __future__ import division
import numpy as np
import duct
duct.xMax = 10
L = 3
d = 1
amp = 0.01
primSrc_pulse1 = duct.MonopoleSource(position=1,
generator=duct.PulseGenerator(amp),
name='Primary source, 1st pulse')
primSrc_pulse2 = duct.MonopoleSource(position=1,
generator=duct.PulseGenerator(-amp, 2*d/duct.c0),
name='Primary source, 2st pulse')
secSrc1 = duct.MonopoleSource(position=1+L,
generator=duct.PulseGenerator(amp, (L+2*d)/duct.c0),
name='Secondary source 1')
secSrc2 = duct.MonopoleSource(position=1+L+d,
generator=duct.PulseGenerator(-amp, (L+d)/duct.c0),
name='Secondary source 2')
duct.animate([primSrc_pulse1, primSrc_pulse2, secSrc1, secSrc2])
# sine waves
if 0:
freq = 50
waveLength = duct.c0 / freq
k = 2*np.pi / waveLength
q1 = 1
#L = waveLength/2 # cancelation in both directions
L = waveLength * 5/8
#L = waveLength * 3/4
#L = waveLength
q2 = -q1 * np.exp(-1j*k*L) # necessary for calculation
primSrc = duct.MonopoleSource(position=1, generator=duct.SineGenerator(q1, freq))
secSrc = duct.MonopoleSource(position=1+L, generator=duct.SineGenerator(q2, freq))
# pulse
else:
primSrc = duct.MonopoleSource(position=3, generator=duct.PulseGenerator(amp=1, delay=0))
L = 2
delay = L/duct.c0
secSrc = duct.MonopoleSource(position=3+L, generator=duct.PulseGenerator(amp=-1, delay=delay))
duct.animate([primSrc, secSrc])
