Hydrophone flow shields
XFlow developed the manufacturing process for PNNL's oil-filled urethane hydrophone flow shields, a precision void-free casting process that required significant process development to achieve acoustic transparency. Field testing confirmed the shields reduce flow noise by over 20 dB below 50 Hz at flow speeds above 0.5 m/s, attenuate propagating sound by no more than 2 dB below 30 kHz, and survived a 6+ month deployment in a tidal channel without degradation, and is ongoing.
Pacific Northwest National Laboratory