Submersible Highly Dense Microphone Arrays for Turbulent Flow Sensing

A tight spatial understanding of turbulent boundary layers and unsteady surface pressure fields is key to reducing acoustic signatures and minimizing flow field energy losses, however, available sensing technology is not integrated and developed enough to deliver the high frequency, high spatial resolution flow field information needed. Therefore in Phase I, Tanner Research Inc. will design a compact turbulent flow microphone sensor array data collection system and conduct preliminary experiments on single sensors and small numbered sensor arrays, to validate key design aspects. Utilizing compact COTS MEMS microphones we will design a 100+ channel microphone array and data recorder system capable of 10kHz data acquisition frequency per sensor. The underwater environment and the high sensor density are key requirements in the selection of the type of microphone and the complexity of the packaging. Tanner will experimentally validate its approach in Phase I via simple underwater data collection and acoustic impedance testing with a few selected sensors and sensor post-packaging configurations. In Phase II, Tanner will re-design, construct, test, and deliver to the Navy a complete prototype underwater turbulent flow data acquisition system that can be tested in a marine environment.