3D flow and deformation measurements of rigid and flexible wings under combined pitching and plunging motions using Lagrangian particle tracking

Abstract

A dynamic test rig based on a hypocycloid gear, designed by F. Huhn 2015, has been manufactured at DLR for underwater flapping wing applications (see Figure 1 a and b). In the frame of the H2020 project HOMER three NACA0012 wings with different flexibility, to be attached to the end plate, have been constructed (half span: 150 mm, chord: 50 mm). The wings perform a two-dimensional motion, i.e. within the x,z-plane, whereas the pitch axis is constantly pointing in the ydirection. Markers with approx. 0.5mm diameter were printed onto the wings with pseudo-random distribution to allow detection of the wing motion and deformation (see Figure 1 c and d). The purpose of the present investigation is to develop advanced experimental methods for the reconstruction of 3D pressure fields and corresponding load distributions on model surfaces in unsteady flows and simultaneously to measure the dynamics of the model deformation by 3D LPT.