抄録
We carried out efficiency comparison experiments of noise and pressure loss reducing devices, ducts put vanes and a board or vanes and a concave wedge shape board made of noise absorbent materials, which are insertion type at a elbow of a wind tunnel.We compared the devices with empty duct and duct put noise absorbent boards to duct's inside four surfaces.We experimented and verified noise reduction performance and pressure loss reduction performance of the devices changing wind tunnel shape and air volume.
