The introduction of new diagnostic techniques in wind tunnels, such as particle image velocimetry (PIV) and pressure-sensitive paint (PSP), has advanced the range of diagnostics with major tools for understanding critical aerodynamic phenomena. At present, PIV is the major diagnostic method to obtain the mean flow-field and turbulent fluctuations. The surface pressure can be measured non-intrusively with PSP, but there is essentially no means to conveniently access the pressure inside the flow. The EU-funded NIOPLEX (Non-intrusive optical pressure and loads extraction for aerodynamic analysis) project contributed to the development of non-intrusive experimental flow diagnostics in order to improve aerodynamic analysis capabilities in research and industrial wind tunnels. Project partners focused on how flow-field pressure measurement by PIV can be further developed to reach a stage where it can be applied to industrial problems. For this purpose, they assessed the performance of different methodologies that have been previously proposed or are currently under development. To develop a comprehensive diagnostic approach, scientists simultaneously measured the surface pressure distribution on a model and the velocity and pressure field around it. They demonstrated the measurement procedures on test cases relevant to industrial research. Specific measurement protocols were formulated and evaluated to ease their use. The NIOPLEX team compared the PIV-based approach with PSP to determine if it can serve as a complement to or possible replacement for PSP. NIOPLEX supported the design of improved aeronautical transport systems with better and more flexible flow-pressure diagnostics that are suitable for aerodynamic performance analysis. These capabilities can impact the design process at an early stage with the use of additional experimental data and diagnostic capabilities during the development cycle. Project work should provide a clear scenario on viable technologies for enhanced pressure analysis capabilities in aerodynamic flows. In this way, it will assist potential operators on using the innovative technique in practice.
Aerodynamic analysis, aeronautical transport systems, particle image velocimetry, pressure-sensitive paint, NIOPLEX