Does anyone know how to make a duct silencer?

Question

I am planning to exhaust the flow entering my chamber via high velocity jet, i have a diffuser and an exhaust fan and i wish to put a silencer between the two. Since the diameter of the duct is quite large, the silencer length is also quite long. So my advisor suggested to convert the diffuser into a silencer along with being a diffuser. I looked up silencer designs and found out that a perforated lined with absorbent material could do the trick. But I don't know what material the perforated duct needs to be made of, the perforation size and spacing and the thickness of the sound absorbent material.

Can somebody help me with this?

Answer 1

try heavy plastic like they use for sewer pipes there is alot of different diameters and different Gage's