# Grazing incidence on an acoustic tile, how to determine grazing angle?

• acousticsnoob
Overall, this problem requires some calculations and plotting to determine how close the angle of incidence needs to be to grazing angle in order to achieve a sound pressure level of less than 83 dB at the surface of the tile. In summary, this problem involves using the given information to calculate the absorption coefficient at different angles of incidence and determine the angle where the resulting sound pressure level is less than 83 dB.
acousticsnoob

## Homework Statement

Acoustic tile which is locally reacting, for a frequency of 400 Hz, it has a normal-incidence specific impedance of 1500+i3700 (Kg/m2s). A plane wave in Air of 400 Hz sound with a pressure level of 86 dB in the absence of reflection is incident on the tile at an Angle X. How close must X be to grazing incidence for resulting sound presure level just at the surface of tile to be less than 83 dB? determine and plot the absorption coefficient as a function of the incidence angle X.

how do i solve this problem?

## Homework Equations

for air, rho*c=400.
Grazing angle X is to be close to 90 degrees. but how do i calculate this angle for given SPL levels of 86 dB and 83 dB?

## The Attempt at a Solution

I'm not sure how to solve this problem. I think it involves using the specific impedance of the acoustic tile, the air pressure level, and the angle of incidence to calculate the absorption coefficient at each angle. Then, I would need to calculate the angle where the resulting sound pressure level is less than 83 dB. After that, I can plot the absorption coefficient as a function of the incidence angle.

## 1. What is grazing incidence on an acoustic tile?

Grazing incidence refers to the angle at which sound waves strike an acoustic tile. It is the angle between the incoming sound wave and the surface of the tile, measured from the surface normal.

## 2. Why is it important to determine the grazing angle on an acoustic tile?

Determining the grazing angle is important because it affects the reflection and absorption of sound waves on the tile. It also impacts the overall acoustic performance of the tile.

## 3. How do you measure the grazing angle on an acoustic tile?

The grazing angle on an acoustic tile can be measured using a laser vibrometer, which measures the displacement of the surface caused by the sound wave. This data can then be used to calculate the grazing angle.

## 4. What factors can affect the grazing angle on an acoustic tile?

The grazing angle on an acoustic tile can be affected by the surface texture and material of the tile, as well as the frequency and intensity of the sound waves.

## 5. How can the grazing angle be adjusted on an acoustic tile?

The grazing angle can be adjusted by changing the positioning of the tile, using different materials or surface treatments, or by altering the frequency or intensity of the sound waves.

• Introductory Physics Homework Help
Replies
1
Views
791
• Classical Physics
Replies
17
Views
1K
• Classical Physics
Replies
15
Views
757
Replies
4
Views
2K
• Introductory Physics Homework Help
Replies
11
Views
6K
• Introductory Physics Homework Help
Replies
16
Views
2K
• Introductory Physics Homework Help
Replies
6
Views
2K
Replies
4
Views
12K
• Introductory Physics Homework Help
Replies
1
Views
1K