PIV stands for ‘particle image velocimetry’, and it is a method to quantitatively measure fluid motions. We use this method to study the aerodynamics of animal flight.
Flying animals generate flight forces by transferring momentum to the wake. The resulting induced air velocities can be measured using a PIV system. Using these results the aerodynamic forces can be deduced, and flight performance and efficiencies can be estimated.
In 2000 we installed our first generation PIV system that was used to study the wake dynamics of a range of birds and of one bat species. In 2008 our second generation PIV system was installed. This system can measure the wake dynamics 200 times per second and is stereoscopic, thus can measure air movements in three dimensions. This system is currently used to study the aerodynamics of birds, bats and insects.
Schematic on the PIV method. The high-speed camera(s) take two snapshots of the fog particles that are illuminated by the laser. From these images, a correlation routine is used to calculate velocity vectors.
Last modified 16 Oct 2012