Using 2D-PIV measurements to compute unsteady aerodynamic loads on a flat plate at high angle of attack

This work exposes and discusses results obtained for aerodynamic forces
using an indirect calculation based on Particle Image Velocimetry (PIV) measurements.
The methodology used is based on the integral formulation of the Navier-Stokes equations
and is applied to spatio-temporal data for different flows around a plate with a 16:1
chord-to-thickness ratio at high angle of attack. Experimental data are obtained in a
water channel for both a static and a pitching plate. In addition to PIV data, direct
measurements of aerodynamic loads are carried out to assess the quality of the indirect
calculation. It is demonstrated that this indirect method is able to compute the mean
and the temporal evolution of the lift and drag coefficients with a reasonable accuracy.
It is also shown that the noise sensitivity of the method can be partly alleviated through
the use of Dynamic Mode Decomposition (DMD) as a pre-processing step to smooth the
spatio-temporal data.