Dense velocity reconstruction with VIC-based time-segment assimilation

Abstract The vortex-in-cell time-segment assimilation (VIC-TSA) method is introduced. A particle track obtained from a finite number of successive time samples the tracer’s position and velocity can be used for reconstruction on Cartesian grid. Similar to VIC + technique, makes use paradigm produce estimates flow state at locations times other than measured ones. working principle requires time-resolved measurements particles’ during interval. work investigates effects assimilated length spatial resolution field reconstruction. hypotheses VIC-TSA are presented here along with numerical algorithm its application tracks datasets. novel parameter governing chosen data assimilation. Three regimes operation identified, based geometrical distance between neighbouring tracks. regime adjacent arguably provides optimal trade-off computational effort. evaluated first by exercise; 3D sine wave lattice reconstructed different values particles concentration. modulation appears reduce (cut-off delay) when increased. Large-scale PIV experiments in wake circular cylinder Re d = 27,000 evaluate method’s suitability real data, including noise outliers. Both primary vortex structures Kármán as well interconnecting ribs present this complex field, typical diameter close average inter-particle distance. When increased beyond, more regular dependence local Lagrangian properties observed, confirming accurate sparse data. Graphical abstract