Frequency Response of Fast-Responsive Pressure-Sensitive Paint

Luminescent paint techniques, especially fast-responsive pressure-sensitive paint (PSP), are common in characterizing surface conditions within wind tunnels without disturbing the flow dynamics, while also being cost-effective. PSP contains a luminophore, which decreases in intensity with increasing pressure. With calibration, PSP is used to detect dynamic pressure on surfaces. In this work, platinum (II) meso-tetra(pentafluorophenyl) porphine (PtTFPP) was used as the luminophore for the PSP. The test used a voice coil speaker that generated sinusoidal pressure waves in an acoustic tube to calculate maximum frequency response of a coupon with PSP in the tube. A Kulite pressure sensor monitored pressure, and a waveform generator varied frequencies between 1 and 20 kHz to analyze the PSP's frequency response. By progressively increasing the frequency of the coil speaker, the maximum frequency response of the PSP's was found. The frequency response of the PSP’s determines its ability to resolve fluctuating pressure components during wind tunnel experiments. The frequency response of the PSP’s determines its ability to resolve fluctuating pressure components during wind tunnel experiments. This nonintrusive application of this PSP is used in the Mach 7 Ludwieg Tunnel at The University of Texas at San Antonio, offering understanding of qualitative pressure distributions and fluctuations on wind tunnel models.