Doppler Optical Coherence Tomography (DOCT) for High-Spatial Resolution Near-Wall Fluid Flow Characteristics

Physical Sciences Inc. (PSI) proposes to develop and demonstrate a novel, non-obtrusive system based on a Fourier Domain Doppler Coherent Optical Tomography (FD-DOCT) technique to measure the near-wall fluid velocity profile, skin friction and turbulence characteristics present in high Reynolds number fluid flow. This system will allow fluid velocity profile measurement with high spatial resolution (5 microns) in the 5 to 100 micron region of the wall/fluid boundary and thus provide direct information of the wall shear stress, a quantity of paramount interest to researchers in their efforts to understand turbulent flow and its contribution to drag resistance in fast moving aerospace vehicles. For this application the capabilities of this technique, with regard to spatial resolution, speed of measurement and ability to function in highly turbulent flows, will exceed those of the traditional techniques such as Hot Wire Anemometry, standard Laser Doppler Velocimetry and Particle Imaging Velocimetry.