Momentaufnahme der Strömung in einer Drallflamme. Die Darstellung der Stromlinien zeigt deutlich die Wirbelstrukturen in den Scherschichten des Strömungsfeldes. Particle image velocimetry (PIV) is the preferred measurement technique for 2D measurement of all three velocity components in turbulent flames. By means of light scattering from small metal oxide particles added to the flow, the path covered by particles and hence the flow velocity is determined by double-pulse illumination. Both mean values and fluctuations in flow velocity can be determined, and turbulent structures can be visualised. In addition to tests on laboratory flames, this technique is also used to characterise combustion processes under real conditions in gas turbines.