Highly-Resolved Wall-Shear-Stress Measurement in High Speed Flows

The Interdisciplinary Consulting Corporation (IC2), in partnership with the University of Florida (UF) and Innoveering, LLC, proposes to develop an innovative precision micro-scale surface-mountable sensor for measuring local wall shear stress in [a] high speed flow field (approximately 0.8 < M < 5) to enable characterization of critical boundary layer flows in ground and flight tests in response to AF14-AT08: Highly-Resolved Wall-Shear-Stress Measurement in High Speed Flows.The proposed sapphire optical wall shear stress and dynamic pressure sensors will enable characterization of complex hypersonic flow environments in ground and flight test facilities at temperatures up to 1200K. The proposed wall shear stress sensor consists of a miniature floating element sensor possessing optical gratings on a floating element and support wafer that form segments of a moir fringe.The pressure sensor utilizes a single sapphire optical fiber to detect the deflection of a reflective sapphire diaphragm.Optical transduction of the moir fringe and diaphragm deflections are achieved via high-temperature sapphire optical fibers, enabling flush-mounted sensor packages.The high-temperature optical fibers can be several meters long and are attached to a photodiode array on the non-sensing end, allowing for the electronics to be remotely located.The Interdisciplinary Consulting Corporation (IC2), in partnership with the University of Florida (UF) and Innoveering, LLC, proposes to develop an innovative precision micro-scale surface-mountable sensor for measuring local wall shear stress in [a] high speed flow field (approximately 0.8 < M < 5) to enable characterization of critical boundary layer flows in ground and flight tests in response to AF14-AT08: Highly-Resolved Wall-Shear-Stress Measurement in High Speed Flows.The proposed sapphire optical wall shear stress and dynamic pressure sensors will enable characterization of complex hypersonic flow environments in ground and flight test facilities at temperatures up to 1200K. The proposed wall shear stress sensor consists of a miniature floating element sensor possessing optical gratings on a floating element and support wafer that form segments of a moir fringe.The pressure sensor utilizes a single sapphire optical fiber to detect the deflection of a reflective sapphire diaphragm.Optical transduction of the moir fringe and diaphragm deflections are achieved via high-temperature sapphire optical fibers, enabling flush-mounted sensor packages.The high-temperature optical fibers can be several meters long and are attached to a photodiode array on the non-sensing end, allowing for the electronics to be remotely located.