2nd LPT and DA challenges: challenges still running, using the present portal!
Following the 2020 1st Challenge edition, the 2nd Challenge gathers several test cases aiming at assessing and comparing the performance of Lagrangian Particle Tracking (LPT) and Data Assimilation (DA) approaches. Test cases of the present challenge are more numerous and diverse than in the 1st edition, in the idea of assessing a larger variety of parameters. Participants are free to compete on a single acquisition modality (e.g., two-pulse Lagrangian Particle Tracking), or on several of them.
Several cases are available for both LPT and DA, and are thus described on separate pages: LPT cases and DA cases, together with participation rules. Guidelines for data formatting are contained in each dataset's description.
A first phase has been organized, with data released in Jan. 2025, result submission by the participants end of Apr 2025, and presentation of the results in Tokyo on June 25, 2025, during a dedicated workshop held in between the ISFV21 and ISPIV2025 conferences. Slides shown during this workshop are free to download!
The challenges will be running for a few more months, in order to collect even more results (and/or possibly refined ones), until all results published on the portal are gathered for being described in journal publications. Stay tuned for the announcement of the final deadline by which you should publish your results!
For any question about these challenges, please do not hesitate to contact the organizers! For questions pertaining to a dataset, contact address for questions are given on the related description page of the dataset.
2nd LPT and DA challenge: LPT cases
Three LPT cases are available, each with a different assessment objective:
- Case 1 contains time-resolved (TR) synthetic data of a turbulent channel flow, at a seeding density of 0.1 particles per pixel (ppp), for three different time separations between the pulses.
- Case 2 consists of synthetic two-pulse (TP) and TR acquisitions of a near-wall flow downstream of cylindrical obstacles. Datasets explore various seeding densities, as well as the influence of two geometrical effects (Mie scattering considered or not, field viewed by all or only a subset of the cameras, controlled by the "I/U" ratio, between the volumes of the intersection and union of cameras' fields of view)
- Case 3 is an experimental test case, whereby Rayleigh-Bénard Convection is investigated using TP and TR sequences, at various seeding densities.
2nd LPT and DA Challenge: DA cases
Three DA cases are available, each addressing different physics:
- Case 1 contains two-pulse (TP), four-pulse (FP) and time-resolved (TR) sequences of an incompressible turbulent channel flow, at various seeding densities
- Case 2 consists of TR sequences of a compressible turbulent boundary layer at a Mach number of 4.9. Parameters explored are the separation time between pulses, the seeding density, and the inertial or non-inertial character of particles
- Case 3 consists of TR sequences of Rayleigh-Bénard Convection at various seeding densities
