# 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.


* The transparency model of the geometry is shown below


* The wireframe model of the geometry is shown below


* 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


* Anechoic termination


* Housing section


* liner


* 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


* 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 $1000Hz$
* frequency $1015Hz$
* frequency $1030Hz$
* frequency $1100Hz$
* frequency $1200Hz$
* frequency $1300Hz$
* frequency $1400Hz$
* frequency $1500Hz$
* frequency $1600Hz$
* frequency $1800Hz$
* frequency $2000Hz$
* frequency $2500Hz$
* frequency $3000Hz$
* frequency $4000Hz$

* Velocity contours are shown as below
* frequency $4000Hz$

* Sound pressure level contours are shown as below
* frequency $1000Hz$
* frequency $1030Hz$
* frequency $1100Hz$
* frequency $1200Hz$
* frequency $1300Hz$
* frequency $1400Hz$
* frequency $1500Hz$
* frequency $2000Hz$
* frequency $2300Hz$
* frequency $2500Hz$
* frequency $2600Hz$
* frequency $2800Hz$
* frequency $3000Hz$
* frequency $3500Hz$
* frequency $4000Hz$

* These are the above results that I have obtained from the above geometry of impedance tube (rig)