Measurement of Continuous Pressure and Shear Distributions Using Coating and Imaging Techniques

Abstract

The pressure-sensitive paint (PSP) method and the shear-sensitive liquid crystal coating (SSLCC) method were sequentially applied to measure the areal pressure and shear stress vector distributions on a planar test surface beneath an inclined, axisymmetric, turbulent impinging jet. The combined results provide the first-ever consolidated measurements of the continuous normal and tangential force distributions beneath a fundamental flowfield. Results indicate that the PSP method can be extended to the measurement of small pressure differences (< ∼0.1 psig) encountered in low-speed atmospheric flows. Further, these results provide the first demonstration of the capability of the SSLCC method to measure continuous shear stress vector distributions on planar surfaces beneath flowfields where shear vectors of all possible orientations are present