COMBINED VISUALIZATION AND MEASUREMENTS IN TRANSITIONAL BOUNDARY-LAYERS

Combined visualisation, velocity and wall pressure measurements are ca rried out in transitional boundary layers. The image of a coherent str ucture is correlated with the variations in wall pressure and both com ponents of velocity. The most important results shows that high wall p ressure peaks are generally located upstream of the ejection observed through visualisation. The simple analysis of the positive peaks of wa ll pressure therefore constitutes a criterion for detecting ejection.