Modern image based experimental methods for application in fluid dynamics

Abstract

Experimental methods for the investigation of complex flow phenomena have primarily been developed for applications to problems of industrial interest such as aerodynamics. Mostly point-wise methods to determine flow velocity, pressure, temperature, density etc. have been utilized in the past. One disadvantage of these methods is that they require a probe to be inserted in the flow field, i.e. the flow phenomenon to be studied may be influenced by the presence of the probe. Due to the recent technological progress (lasers, optoelectronics, high resolution high-sensitive video sensors, processing speed and memory capacity of computers, development of advanced evaluation and post-processing algorithms) image based measurement techniques have been developed which allow to observe flow phenomena from a large distance. These image based methods have found application as standard and robust measurement techniques for aerodynamic investigations in industrial wind tunnels in the past decade. Inparallel they are more and more often used for the investigation of flows in nature as weIl. An overview of the most important image based measurement techniques as weIl as an assessment oftheir potential to be used for flows in nature will be given.