Pressure Sensitive Paint Application in Low-Speed Flows

Pressure field measurements on a wing profile are conducted to evaluate the accuracy of measurement system using (40-60 m/sec) enviroments. A part of the wing surface was coated with binary paint B1 from Optrod Ltd. Two different light sources, a Xenon - flash lamp and a nitrogen-laser were used for paint excitation and the resulting fluorescence fields in two spectral band length were acquired by 16 bit CCD slwo scan camera with appropriate filters. Results shows that the optical pressure measurement system with binary paint can achieve pressure resolution better than 1 mba

Pressure Sensitive Paint Measurements on a Wing Model in a Low-Speed Wind Tunnel

Pressure field measurements on a wing profile are conducted to evaluate the accuracy of a measurement system using the so called 'binary' or 'two-color' Pressure Sensitive Paint (PSP) for low-speed (40-60m/sec) environments. A part of the wing surface was coated with a binary paint. Two different light sources, a high pressure Xenon-flash lamp and a nitrogen laser were used for the excitation of the paint. The resulting fluorescence fields were acquired by a 16-bit-CCD slow-scan camera. In front of this camera two different optical devices, a filter-shifting system or alternative a beam-splitting system, each of them were equipped with appropriate optical filters to separate the two different spectral emission wavelength of the paint, were used. Results shows that this optical pressure measurement system is able to resolve the small pressure changes on the model surface. Due to model movement and model deformation in between the image acquisition of the 'wind-off' and 'wind-on' images the necessity to use a binary paint for precise pressure measurements is clearly visible. These PSP-System working with binary paint can achieve pressure resolution in the region of 1 mba

Flow visualization in a low-density plasma channel

A schlieren system and surface-stress-sensitive film system were developed for a plasma channel which posed unique challenges for flow visualization because of the combination of low air density and the presence of plasma discharges. Temperature-sensitive paint and direct-current discharge were also applied to flow visualization. Three pulsed schlieren light sources were evaluated. A light-emitting diode (LED), a xenon NanopulserTM and laser breakdown, were tested on identical flowfields. The LED provided excellent illumination, with pulses ranging from μs to continuous. The NanopulserT