Real-time Flow Field Measurement under Predetermined Control by Plasma Acutuator using Sparse Processing PIV

Flow field with predetermined control by the pair of plasma actuators (PA) was measured in real time using sparse processing particle image velocimetry (SPPIV), where SPPIV is a method to estimate the entire flow field from limited results of sparsely located particle-image-velocimetry (PIV)-analysis interrogation window. In this study, the PIV measurement was conducted for cylinder model under the following conditions; the freestream velocity, the diameter, and the position to attach the pair of PAs were 5 m/s, 30 mm, and a point on each side at 90° from the centerline in the freestream direction, respectively. Several proper orthogonal decomposition (POD) modes were used and the velocity field was estimated by SPPIV. The results of the analysis showed that the flow velocity field can reconstruct a large-scale structure with the upper two modes, and can be measured with very high estimation accuracy even with a small number of sensors (e.g., five). We also added information on the control input term to the estimation model and investigated changes in estimation accuracy under control by the pair of PAs. In the future, feedback control with SPPIV and PAs as the observer and the actuator is being planned, and the technologies for this have been sufficiently investigated.