Acoustic material
Where it is
Section titled “Where it is”Not a setup-tree node. Embedded in the application.
Controls
Section titled “Controls”MATERIAL
Section titled “MATERIAL”Material
Section titled “Material”- Control: choice (
ComboRow) - Shown when:
!root.thermoviscous
Browse…
Section titled “Browse…”- Control: action (
ToolButton2)
Density ρ
Section titled “Density ρ”- Control: value (
ValueField) - Unit: kg/m³
- Value modes: none (plain entry)
Sets the impedance ρc together with the sound speed below, which is what turns a driven velocity into a pressure.
Sound speed c
Section titled “Sound speed c”- Control: value (
ValueField) - Unit: m/s
- Value modes: none (plain entry)
343 in air at 20 °C, 1481 in water. Every wavelength and every resonance in the answer scales with this number directly.
THERMOVISCOUS PROPERTIES
Section titled “THERMOVISCOUS PROPERTIES”Kinematic viscosity ν
Section titled “Kinematic viscosity ν”- Control: value (
ValueField) - Unit: m²/s
- Value modes: none (plain entry)
- Shown when:
root.thermoviscous
Times the density, this is the dynamic viscosity Elmer’s solver actually reads.
Bulk viscosity ζ
Section titled “Bulk viscosity ζ”- Control: value (
ValueField) - Unit: Pa·s
- Value modes: none (plain entry)
- Shown when:
root.thermoviscous
Rarely published. Left at zero assumes the Stokes hypothesis, the ordinary assumption in its absence - not that the material has none.
Thermal conductivity k
Section titled “Thermal conductivity k”- Control: value (
ValueField) - Unit: W/m/K
- Value modes: none (plain entry)
- Shown when:
root.thermoviscous
Specific heat Cp
Section titled “Specific heat Cp”- Control: value (
ValueField) - Unit: J/kg/K
- Value modes: none (plain entry)
- Shown when:
root.thermoviscous
At constant pressure, as every table publishes it. Elmer’s Material block wants Cv; the deck divides by the ratio below.
Specific heat ratio γ
Section titled “Specific heat ratio γ”- Control: value (
ValueField) - Value modes: none (plain entry)
- Shown when:
root.thermoviscous
Cp/Cv. 1.4 for a diatomic gas like air, 1.67 for a monatomic one like helium or argon.
Reference temperature
Section titled “Reference temperature”- Control: value (
ValueField) - Unit: K
- Value modes: none (plain entry)
- Shown when:
root.thermoviscous
The equilibrium state the small-amplitude disturbance is linearized about - 293.15 K is 20 °C.
Problems reported against this step
Section titled “Problems reported against this step”The application reports no problems against this step.
… marks a value the application computes at run time, so the source carries no fixed text for it.