---
# System prepended metadata

title: REPORT OF THE FIRST RESULTS OBTAINED FROM OUR SIMULATIONS OF ACOUSTIC LINER

---

# REPORT OF THE FIRST RESULTS OBTAINED FROM OUR SIMULATIONS OF ACOUSTIC LINER 

## GEOMETRY
* The geometry we made consists of two sections, up stream and down stream i.e, both sections are symmetrical. Each section consists of tube of length $1m$ and anechoic chamber is used to absorb the sound which is generated from the sound source i.e, loud speaker.The geometry is shown below.

![](https://i.imgur.com/g6PQJvQ.jpg)

* The transparency model of the geometry is shown below

![](https://i.imgur.com/z7Bts9J.jpg)

* The wireframe model of the geometry is shown below

![](https://i.imgur.com/9fQ3mVm.jpg)

* Each sections of the geometry are made seperately and they are finally assembled to make the final geometry. 

* Sections of the geometry are shown below
    * Circular tube

    ![](https://i.imgur.com/VVAylrD.jpg)
    
    * Anechoic termination
    
    ![](https://i.imgur.com/hfOOv9O.jpg)
    
    * Housing section

    ![](https://i.imgur.com/rpFVi6Y.jpg)
    
    * liner
    
    ![](https://i.imgur.com/AkblJG8.jpg)

* Materials used for the analysis
    * For tube and anechoic termination - A2 steel
    * For liner section - Nickel(commercially pure)

* Meshing 
    * Complete mesh consists of $124231$ domain elements, $81186$ boundary elements, and $3463$ edge elements
    * The image of meshing is shown as below and the element size is finer
    
    ![](https://i.imgur.com/RwQXx8c.jpg)

* Physics used
    * There are two types of physics used pressure-acoustics frequency domain and pipe-acoustics frequecncy domain
    
* Boundary conditions
    * The pressure at the source is 2Pa and at the end of the anechoic end the reflection coefficient $(|R|=0.2)$
    
* Study
    * The study used is frequency domain and the frequency range is $1000Hz- 4000Hz$ with in steps of $5Hz$
    
* Results
* Acoustic pressure contours are shown as below
    * frequency $1000Hz$
    ![](https://i.imgur.com/32n91q6.jpg)
    * frequency $1015Hz$
    ![](https://i.imgur.com/fZoM0EX.jpg)
    * frequency $1030Hz$
    ![](https://i.imgur.com/bgeQh1q.jpg)
    * frequency $1100Hz$
    ![](https://i.imgur.com/NdPTBm5.jpg)
    * frequency $1200Hz$
    ![](https://i.imgur.com/BVD6Oj7.jpg)
    * frequency $1300Hz$
    ![](https://i.imgur.com/EY9iogi.jpg)
    * frequency $1400Hz$
    ![](https://i.imgur.com/Ir9M5px.jpg)
    * frequency $1500Hz$
    ![](https://i.imgur.com/gQ2Fmyg.jpg)
    * frequency $1600Hz$
    ![](https://i.imgur.com/FAMEgg6.jpg)
    * frequency $1800Hz$
    ![](https://i.imgur.com/nbXJwxT.jpg)
    * frequency $2000Hz$
    ![](https://i.imgur.com/JDlXZg3.jpg)
    * frequency $2500Hz$
    ![](https://i.imgur.com/iQfEIxb.jpg)
    * frequency $3000Hz$
    ![](https://i.imgur.com/z4Ea5DD.jpg)
    * frequency $4000Hz$
    ![](https://i.imgur.com/hr147pB.jpg)

* Velocity contours are shown as below
    * frequency $4000Hz$
    ![](https://i.imgur.com/DeKPEfp.jpg)
    
* Sound pressure level contours are shown as below
    * frequency $1000Hz$
    ![](https://i.imgur.com/UtblVRo.jpg)
    * frequency $1030Hz$
    ![](https://i.imgur.com/OJvQxcS.png)
    * frequency $1100Hz$
    ![](https://i.imgur.com/PIVvL0B.jpg)
    * frequency $1200Hz$
    ![](https://i.imgur.com/1Lf7dl9.jpg)
    * frequency $1300Hz$
    ![](https://i.imgur.com/MCUKcqc.jpg)
    * frequency $1400Hz$
    ![](https://i.imgur.com/59y4vCs.jpg)
    * frequency $1500Hz$
    ![](https://i.imgur.com/GPEemFE.jpg)
    * frequency $2000Hz$
    ![](https://i.imgur.com/fnGZL0S.jpg)
    * frequency $2300Hz$
    ![](https://i.imgur.com/i1vnMZh.jpg)
    * frequency $2500Hz$
    ![](https://i.imgur.com/72EkNzn.jpg)
    * frequency $2600Hz$
    ![](https://i.imgur.com/4T6Ph8G.jpg)
    * frequency $2800Hz$
    ![](https://i.imgur.com/SICP9zC.jpg)
    * frequency $3000Hz$
    ![](https://i.imgur.com/PRLyLvd.jpg)
    * frequency $3500Hz$
    ![](https://i.imgur.com/WPivzFW.jpg)
    * frequency $4000Hz$
    ![](https://i.imgur.com/o8O178Y.jpg)
    
* These are the above results that I have obtained from the above geometry of impedance tube (rig)