A Low-Profile Flow Shear Sensing Unit

Summary

UCLA researchers have developed an accurate low-profile shear sensing unit that is viable for both gas and liquid flows.

Innovation

UCLA researchers have developed a low-profile sensing unit that measures the shear stress of fluid flows in a direct manner. The unit suspends a plate with micro-flexures and reads its displacement with an optical encoder through innovative engineering that produces high sensitivity, accuracy, and spatial and temporal resolution. The unit is immune to electromagnetic interference and is valid for repeated use in any fluids, including both air and water.

Applications

• Aerospace and aeronautical skin friction measurements
• Hydrodynamic skin friction measurements
• Complex flow measurements
• Signal feedback
• Drag determinations of man-made structures

Advantages

• Low profile to imbed into the wall surface
• High sensitivity and accuracy
• High spatial and temporal resolution
• Immune to pressure and temperature variations
• Immune to electromagnetic interference
• Can be used repeatedly

State Of Development

The invention has been successfully prototyped and demonstrated. Variations of units have been developed and actively being used for internal projects.

Patent Status

Related Materials

• Bao, Xiaoqi, et al. "Sensor for direct measurement of the boundary shear stress in fluid flow." SPIE Smart Structures and Materials+ Nondestructive Evaluation and Health Monitoring. International Society for Optics and Photonics, 2011.