Live-Optical Flow Velocimetry

Our Fluid mechanics expert (Juan Pimienta) demonstrating Live-Optical Flow Velocimetry (Live OFV) measurements with our solution eyePIV. 
The video shows a flow control experiment aiming at reducing the size and dynamics of the recirculation bubble generated downstream a Backward-Facing Step (BFS) using a set of Counter-Rotating Jet Vortex Generators (CR-JVG) located upstream of the step edge.

The measurements are carried out in a horizontal plane close to the lower wall to illustrate the spanwise modification of the flow induced by the jets.  
The instantaneous dense (1 vector per pixel) 2D velocity fields are computed Live at 100 Hz from 8.192 Mpx images (sampling frequency of the camera of 200 FPS and treated as isolated pairs).

Measurements were performed at the PMMH laboratory from ESPCI Paris-PSL, where this innovative Live-OFV has been first developed for flow control experiments before being transferred, developed and optimized through 2 successive PhD thesis by Photon Lines supported. This strong collaboration to develop further Real-Time optical measurements for fluid mechanics applications benefits now from a LabCom project (Common Laboratory associating Photon Lines and the PMMH laboratory) for the next 5 years with the financial support of the ANR (Agence Nationale de la Recherche). We thank Jean-Luc Aider (DR CNRS), head of the Flow Control team of the PMMH lab, for this long-term and fruitful collaboration.

For further information about our measurement method, take a look at our last preprint : https://arxiv.org/pdf/2509.25924