Application of Pressure Sensitive Paint -Theory and Practice-

Abstract

For investigations of pressure distributions on wind tunnel model surfaces with high spatial resolution new experimental techniques, such as Pressure Sensitive Paint (PSP) are required. Using this non- intrusive optical pressure measurement technique, spatial structures and/or rapid temporal or spatial changes of aerodynamic phenomena (transition from laminar to turbulent flow, coherent structures, pitching airfoils in transonic flows with shocks, rotors, test facilities with short run time and different flow temperature etc.) can be investigated. Recently an increasing number of scientists and engineers have started to utilise the PSP technique to investigate pressure distributions from low speed up to hypersonic and cryogenic wind tunnels as well as in turbo machines. The PSP technique has also expanded from the measurement of steady state pressures to include both periodic and unsteady phenomena to study the instantaneous structure of pressure fields in various areas of fluid mechanics. A number of different approaches for paint development, recording and evaluation of PSP images have been described in the literature. This course, which is the third one on PSP organised by DLR Göttingen, Germany, will mainly concentrate on both industrial measurement techniques as well as aspects of the theory of PSP relevant to applications. In addition to lectures on the fundamental aspects of Pressure Sensitive Paint Systems, special emphasis is placed on the presentation of practical and reliable solutions for problems faced during the implementation of the technique in wind tunnels and other test facilities. During practical sessions on the course, participants will have the opportunity to carry out experiments on paint characterisation, coating technique, and the recording and evaluation of PSP data in small groups. Recent developments of the PSP technique such as PSP for unsteady applications and 360° PSP systems for calculation of forces and moments will be discussed and demonstrated.