Fully Coupled Analysis (Sound Wave Drive)examples|products|Murata Software Co., Ltd.

Example3 Fully Coupled Analysis (Sound Wave Drive)

General

  • The drive from the sound wave domain is analyzed. The sound pressure is solved as the floating electrode voltage of the piezoelectric material.

 

Analysis Space

Item

Settings

Analysis Space

3D

Model unit

m

 

Analysis Conditions

Item

Settings

Solvers

Piezoelectric Analysis [Rayleigh]

Acoustic Analysis [Mach]

Analysis Type

Harmonic analysis

Options

Select “Fully coupled analysis”

The harmonic analysis tab is set up as follows.

The sound waves propagate outside the analysis domain. Therefore the “open boundary” condition below is applied initially.

Tab

Setting Item

Setting

Harmonic Analysis

Frequency

10×10^3[Hz]

Sweep Type

Single frequency

Open Boundary Tab

Type

Absorbing boundary

Order of Absorbing Boundary

1st degree

Coordinates of Origin

x = y = z = 0

 

Graphical Objects

Piezoelectric materials are placed around the respiratory sphere used in the Exercise 4. The sound pressure is measured. 5 semicircle piezoelectric materials are placed around the respiratory sphere for measurement. As shown below, one piezoelectric material has ground and floating electrode. The pressure is detected by the voltage of the floating electrode.

 

Body Attributes and Materials

Body Number/Type

Body Attribute Name

Material Name

4/Solid

Air

000_Air(*)

5/Solid

Piezoelectric material_000

000_P-4 *

6/Solid

Piezoelectric material_045

000_P-4 *

7/Solid

Piezoelectric material_090

000_P-4 *

8/Solid

Piezoelectric material_135

000_P-4 *

9/Soid

Piezoelectric material_180

000_P-4 *

* Available from the Material DB

Boundary Conditions

Boundary Condition Name/Topology

Tab

Boundary Condition Type

Settings

VEL/Face

Acoustic

Speed

1[m/s]

Open/Face

Acoustic

Open boundary

 

FIX

Mechanical

Displacement

UX=0, UY=0, UZ=0

UY0

Mechanical

Displacement

UY=0

V0

Electric

Voltage

0[V]

FLOAT_000~FLOAT_180

Electric

Floating electrode

 

 

Results

The sound pressure distribution is shown as follows. For comparison purpose, the model with piezoelectric materials removed is shown.

 

Result 1 (a) The sound pressure distribution of the model with piezoelectric materials removed Result 1 (b)The sound pressure distribution of the model including piezoelectric materials (for reference)

The voltage of the floating electrodes are shown on the right side of the figure.

 

 

 

 

We can observe that the sound waves are obstructed by the piezoelectric materials.

The figure below is the view in the + X direction of the figure above with piezoelectric materials shown. The colors of the semicircles indicate the floating electrode voltages. The numbers on the right side of the piezoelectric materials are the floating electrode voltages.

The respiratory sphere has large sound pressure and the voltage is large in its front. We can consider that the voltage is obtained corresponding to the sound pressure.