Home / Examples / Acoustic Analysis [Mach] / Example 6: Reflection and Diffraction

Example 6: Reflection and Diffraction

 

General

 

• Sound waves reflect and diffract at a rigid wall.
   

• Unless specified in the list below, the default conditions will be applied.
   

• Obtain this session's project file. (Right-click and choose 'Save link as')




• Results will vary depending on Femtet version and the PC environment.

 

Analysis Space

Item	Settings
Analysis Space	2D
Model Unit	mm

 

Analysis Conditions

Item	Settings
Solver	Acoustic Analysis [Mach]
Analysis Type	Harmonic Analysis
Options	N/A

 

 

Tab	Setting Item	Settings
Harmonic Analysis	Frequency: Sweep Values	10 [kHz]
	Frequency: Sweep Type	Single Frequency
	Frequency Sweep	Discrete Sweep
Open Boundary	Coordinates of Origin	x = 0 y = 0

Model

A rigid wall is placed behind the sounder. The model is enclosed in a circle.

The open boundary condition is set on the circumference.

 

 

 

 

Body Attributes and Materials

Body Number/Type	Body Attribute Name	Material Name
13/Sheet	AIR	000_Air(*)

* Available from the material DB

 

Boundary Conditions

The [Speed] boundary condition is set on the face of the sounder and the [Open boundary] condition is set on the perimeter.

Boundary Condition Name/Topology	Tab	Boundary Condition Type	Settings
v/Edge	Acoustic	Speed	1 [m/s]
OPEN/Edge	Acoustic	Open Boundary

 

Results

The isosurface contour of the sound pressure [Pa] is shown below.

 

 

Most of sound waves reflect at the rigid wall. Some diffraction is observed.