SBIR-STTR Award

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.

Benefit:
A highly compact, high spatial resolution, novel underwater acoustic sensor array for unsteady flow field measurements that has the potential to allow for reduction of acoustic emissions for Navy underwater vehicles and associated sonar equipment.

Keywords:
acoustic measurement, acoustic measurement, Turbulent Boundary Layer Flow, Pressure Sensor Array, Unsteady Pressure Field, Underwater, Noise control, High Channel Count Arrays, Microphones

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. In Phase I, Tanner Research Inc. demonstrated a compact turbulent flow microphone sensor array data collection system utilizing compact COTS MEMS microphones and conducted preliminary experiments on single sensors and small numbered sensor arrays, to validate key design aspects. In Phase II, we plan to design a 100+ channel microphone array and data recorder system capable of greater than 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 II initially via simple underwater data collection and acoustic impedance testing with a few selected sensors and then larger sensor arrays will be tested and optimized in a low speed water channel with researchers at the University of Southern California. Finally, in the Phase II Option 2, Tanner will, construct, test, and deliver to the Navy a complete prototype underwater turbulent flow data acquisition system that can be tested in the Navys high speed water tunnel.

Benefit:
A highly compact, high spatial resolution, novel underwater acoustic sensor array for unsteady flow field measurements that has the potential to allow for reduction of acoustic emissions for Navy underwater vehicles and associated sonar equipment. Initial commercial market size for this measurement technology will mainly be with fluid mechanics research groups around the world ($10M). Similarly, in other domains when used for reducing flow noise and drag there are additional market segments in oil transport (drag reduction), competitive sailing, submersibles, automotive, train and aircraft worth (upwards $50M-$100M). The data collection, read-out electronics including the visualization and analysis software may also have ancillary application areas such as real-time data streaming and visualization for both gas and liquid flow sensor arrays.

Keywords:
Turbulent Boundary Layer Flow, High Channel Count Arrays, Microphones, Pressure Sensor Array, Noise control, Unsteady Pressure Field, acoustic measurement, Underwater