The formula to calculate the Absorption Coefficient (α) is:
\[ \alpha = 1 - \frac{(R + 1)^2}{R + \rho^2} \]
Where:
A porous absorber is a type of material that is capable of absorbing sound waves. It is characterized by its porous structure, which allows sound waves to penetrate into the material and get trapped, reducing the amount of sound that is reflected back. This makes porous absorbers effective for soundproofing and noise reduction applications. Common examples of porous absorbers include foam, fiberglass, and certain types of fabric.
Let's say the reflection coefficient (R) is 0.5, and the density of the porous material (ρ) is 1.2. Using the formula:
\[ \alpha = 1 - \frac{(0.5 + 1)^2}{0.5 + 1.2^2} \approx 0.36 \]
So, the absorption coefficient (α) is approximately 0.36.