Dr.-Ing. Michaela Herr of the Institute of Aerodynamics and Flow Technology of DLR Braunschweig has been awarded the Bertha Benz Prize for her worldwide unique research results on trailing-edge noise reduction. The prize, endowed with a € 10,000 award is presented in the course of the annual Bertha Benz lecture in Heidelberg. In her dissertation, "Trailing-Edge Noise – Reduction Concepts and Scaling Laws," the engineer and biologist has comprehensively studied a fundamental problem of flow acoustics: The so-called trailing-edge noise is produced when air flow passes the trailing-edges of airfoils into the wake. On the basis of extensive experimental studies in the Acoustic Wind Tunnel Braunschweig, Herr managed to analyze the complex trailing-edge noise generation mechanisms as well as to derive general design criteria for future low-noise airfoils. Her scientific work provides a worldwide unique data base. "Through application of flow-permeable porous trailing-edge modifications we were able to reduce the trailing-edge noise by up to 10 dB, that is to say up to 90 %.” It proved to be helpful for her research that the engineer is also a biologist. "In nature there is an interesting analogy: Night-hunting owls fly almost silently thanks to noise-reducing flow-permeable fringes at the trailing edges of their primary feathers. They use this now first-time systematically scaled and experimentally verified noise reduction principle very effectively," explains Herr.