Continuous-field Image Correlation Velocimetry (ICV) determines the optical flow in sequences of images, relying on a convected Lagrangian marker, e.g., a conserved scalar field, or particles, etc. The method extends the original ICV implementation (Tokumaru & Dimotakis 1995) by implementing a hierarchical, multi-resolution B-spline representation, imposing the desired continuity order to the inferred velocity field, also accommodating boundary conditions, as appropriate to the flow domain. The method has been tested on several simulated-flow cases and error results are presented, with and without noise added to the correlated test-images. The results of further tests for two laboratory flows are reported, an accelerated NACA-0012 airfoil at high angle of attack and a transverse jet in a coflowing stream.
This work was supported by the Air Force Office of Scientific Research Grant Nos. F49620-93-0338 and F49620-94-1-0353.