A wind tunnel sensor network for a cost-effective evaluation of aircraft drag reduction from riblets

High quality measurements are of paramount importance to fully investigate complex phenomena in wind tunnel experimentations. This paper outlines the role played by the wind tunnel sensor network for a practical research project where the main goal was to evaluate possible benefits from special coatings on aircraft aerodynamic surfaces. Basically, a wind tunnel model, covered alternatively with a smooth coating and subsequently with a film presenting micro-grooves (riblets), is exposed to flow velocities close to the operational speeds of commercial aircraft to see whether a drag reduction is observed. Drag reduction results in less fuel consumption which makes the technology attractive for airline operators and simultaneously for those involved in the environmental impact of flights. The need of accurate measurements is the key element to demonstrate the technology potential for real applications since even small enhancements, actually, may bring large benefits due to ever growing expansion of the aviation transport.