AcousticNormalVelocityValue
AcousticNormalVelocityValue[pred,vars,pars]
represents a time or frequency domain normal velocity boundary condition for PDEs with predicate pred indicating where it applies, with model variables vars and global parameters pars.
AcousticNormalVelocityValue[pred,vars,pars,lkey]
represents a time or frequency domain boundary condition with local parameters specified in pars[lkey].
Details
- AcousticNormalVelocityValue specifies a boundary condition for AcousticPDEComponent and is used as part of the modeling equation:
- AcousticNormalVelocityValue is typically used to model sound sources on the boundary.
- AcousticNormalVelocityValue models a time or frequency domain normal velocity with dependent variable pressure
in 
, independent variables 
in 
and time variable 
in 
or frequency variable 
in 
. - Time-dependent variables vars are vars={p[t,x1,…,xn],t,{x1,…,xn}}.
- Frequency-dependent variables vars are vars={p[x1,…,xn],ω,{x1,…,xn}}.
- The time domain acoustics model AcousticPDEComponent is based on a wave equation with time variable
, density 
, sound speed 
and sound sources 
and 
: - The frequency domain acoustics model AcousticPDEComponent is based on a Helmholtz equation with angular frequency
: - The time domain normal velocity value AcousticNormalVelocityValue with sound particle velocity
in 
models: - The frequency normal velocity value AcousticNormalVelocityValue models:
- Model parameters pars are specified as for AcousticPDEComponent.
- The following model parameters pars can be given:
-
parameter default symbol "AcousticSoundParticleVelocity" 0 
, acoustic sound particle velocity in 
- AcousticNormalVelocityValue evaluates to a NeumannValue.
- The boundary predicate pred can be specified as in NeumannValue.
- A normal velocity boundary condition can be used with:
-
analysis type applicable Time Domain Yes Frequency Domain Yes Eigenfrequency No - If the AcousticNormalVelocityValue depends on parameters
that are specified in the association pars as …,keypi…,pivi,…], the parameters 
are replaced with 
.
Examples
open allclose allBasic Examples (2)
Scope (4)
Define model variables vars for a transient acoustic pressure field with model parameters pars and a specific boundary condition parameter:
Define model variables vars for a transient acoustic pressure field with model parameters pars and multiple specific parameters boundary conditions:
Define model variables vars for a transient acoustic pressure field with model parameters pars:
Define silent initial conditions ics:
Set up the equation with an acoustic normal velocity boundary with the sound particle velocity v of 
at the left end:
Solve the PDE on a refined mesh:
Define model variables vars for a frequency domain acoustic pressure field with model parameters pars:
Set up the equation with an acoustic normal velocity boundary at the left, the sound particle velocity 
of 
and an acoustic absorbing boundary at the right:
Visualize the solution in the frequency domain at various frequencies 
:
Text
Wolfram Research (2020), AcousticNormalVelocityValue, Wolfram Language function, https://reference.wolfram.com/language/ref/AcousticNormalVelocityValue.html.
CMS
Wolfram Language. 2020. "AcousticNormalVelocityValue." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/AcousticNormalVelocityValue.html.
APA
Wolfram Language. (2020). AcousticNormalVelocityValue. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/AcousticNormalVelocityValue.html