An Affordable Instrument for Pressure-Sensitive Paint Measurements

摘要

New measurement techniques based on pressure-sensitive paints are delivering full field aerodynamicmeasurements in wind tunnel testing. These techniques are based on the oxygen quenching ofluminescence. The intensity of luminescence can be measured and calibrated to indicate pressure. Theinstrumentation traditionally used to measure the intensity of the luminescence usually includes ascientific grade digital camera and customized lighting. The costs typically range from twenty to fiftythousand dollars per camera and can be several thousand dollars per lamp. These systems usuallyincorporate more than one camera and multiple lamps. The costs of these systems prohibit the broad useof this technology by scientists and engineers.A new test instrument has been developed with which point measurements can be achieved. This selfcontainedsystem incorporates a single light source, a single detector, and can be assembled at a fractionof the cost. The system was designed such that the illumination light source could be self-referencedand that luminescence could be sampled in five distinct wavelength bands. Sampling five spectrums oflight allows for the use of multiple-probe coatings. In addition, the illumination light source providesthe option of modulation to retard photo-degradation and to support signal-to-noise ratio enhancement.This low-cost approach to pressure-sensitive paint measurements could expand the use of thistechnology to a new user base that includes individual researchers and small universities.