27 Jun 2001
BAE Systems Advanced Technology Centres is exhibiting SUPREMO, the non-contact pressure measurement system, at the Royal Society Summer Science Exhibition 2001.
SUPREMO, SUrface PREssure Measurement using Optics, provides the ability to measure the pressure and temperature of a surface under examination without using mechanical means. The traditional method of measuring air pressure has been through the use of mechanical devices. SUPREMO makes use of a radical, new method of measuring air pressure, Pressure Sensitive Paint.
In the development of new aircraft design, key performance parameters including aircraft lift and drag, are confirmed through the use of wind tunnel testing generating detailed pressure maps over the surface of scale models. Conventionally, pressure is measured via a limited number of tiny holes over the surface, each connected to a pressure transducer. This approach is time consuming, expensive and crude in an industry where fractions of a percent difference are critical to both cost and performance.
The SUPREMO system replaces the holes and transducers with a layer of paint and an external interrogation system. Wind tunnel models are therefore cheaper and quicker to produce and have more comprehensive surface data coverage. The SUPREMO system works on the principles of the ability of oxygen to de-activate or quench fluorescent substances. The glow of such substances when illuminated varies with the concentration of oxygen present. The paint which is used within the SUPREMO system consists of an organic dye dissolved into a gas permeable polymer which is then applied to the surface of interest.
The BAE Systems Advanced Technology Centres solution to the measurement of pressure is novel in that the response of the paint to pulsed laser light is measured. A laser beam is pointed at the painted model and the response to a very short burst of light is analysed. Rapidly scanning the laser over the surface generates an accurate, real time pressure and temperature map of the area under examination.
The SUPREMO system will enable the designers of the next generation of aircraft to confirm the performance of theoretical airframe designs quickly, efficiently and with confidence, leading to the development of military and civil aircraft with ever higher levels of performance and efficiency.
