COMBINED VISUALIZATION AND MEASUREMENTS IN TRANSITIONAL BOUNDARY-LAYERS

Combined visualisation, velocity and wall pressure measurements are carried out in transitional boundary layers. The image of a coherent structure is correlated with the variations in wall pressure and both components of velocity. The most important results shows that high wall pressure peaks are generally located upstream of the ejection observed through visualisation. The simple analysis of the positive peaks of wall pressure therefore constitutes a criterion for detecting ejection.