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DirectShear Sensors Used in Latest Research out of University of Florida

Posted by Tai-An Chen on Jan 8, 2019 4:09:37 PM

It’s official. Researchers are now directly measuring wall shear stress to help characterize turbulent boundary layers (University of Florida). Results were published in a recent Physical Review of Fluids journal paper (Pabon et al.), “Characteristics of turbulent boundary layer large scale motions using direct fluctuating wall shear stress measurements”. In the paper, a capacitive-based, floating element MEMS sensor was used for skin friction measurement. The goal was to further the understanding of wall shear stress dynamics, focusing on the large turbulent scales.

The study employed direct measurements of wall shear stress along with synchronous sampling of the streamwise velocity field using hot-wire anemometry. The UF capacitive shear stress sensor is a prototype version of the technology at the core of IC²'s DirectShear™ sensor. In the published research, the UF sensor was used to measure a zero pressure gradient turbulent boundary layer over a flat plate model. The results from the UF sensor showed good agreement with existing velocity profile-based literature and direct numerical simulations (DNS).

The graduate student researcher, Rommel Pabon, also used IC²’s DirectShear sensor in his dissertation titled “Experimental Studies of Organized Motions in a Turbulent Boundary Layer and Their Imprint on Wall Shear Stress.”  Additional publications from his dissertation work using the DirectShear sensor system are forthcoming.  
DirectShear Floating Element

Photograph of the IC² DirectShear floating element head used in the UF dissertation (image courtesy of IC²/David Mills)

The DirectShear sensors provide both the spatial and temporal resolution needed to resolve turbulent structures in the flow over a body, while reducing measurement uncertainty. For more information on how IC² DirectShear sensors can enhance your next data-set, click here.

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References:

Pabon, R. J., Ukeiley, L., Sheplak, M., & Keane, C. B. (2018). Characteristics of turbulent boundary layer large scale motions using direct fluctuating wall shear stress measurements. Physical Review Fluids, 3(11), 114604.  https://journals.aps.org/prfluids/abstract/10.1103/PhysRevFluids.3.114604

About IC²

IC²  builds on two decades of research and rigorous testing to deliver scientific-grade precision sensors that push the envelope of aerospace measurement accuracy and performance. IC²’s precision sensors and instrumentation are designed from the ground up to meet the challenging environments of the aerospace industry.

From wind tunnels and other ground test facilities to flight test platforms, IC² delivers scientific-grade measurement tools that provide unprecedented performance, including:

  1. Higher bandwidth and dynamic range
  2. Greater accuracy and precision
  3. Higher spatial resolution
  4. Ability to operate in environments considered too extreme for most sensors 

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Topics: DirectShear, dissertation