Home

Welcome to the ONERA portal for benchmarking of flow reconstruction approaches!

This portal aims at providing a continuous development and benchmark tool for volumetric fluid flow reconstruction approaches. This includes sets of images for determining velocity (and possibly acceleration) vector fields via Lagrangian Particle Tracking (LPT) or Particle Tracking Velocimetry (PTV), and sequences of particle position or tracks in space for reconstructing dense flow fields (velocity and possibly pressure) via Data Assimilation (DA).

Datasets are free to download for everyone. Result upload can be done after creating an account, which also allows to receive regular news by email that we will issue about the portal (see News section below). Uploading a result in order to get an evaluation can be done without publishing the evaluation on the portal. For more information consult the Submission rules.

This portal will be in continuous development, with new test cases regularly added. External participation is also welcome! In case you are interested in suggesting a test case, please feel free to contact us at flow-benchmarks@onera.fr.

Available datasets

• Second LPT Challenge: challenge is still running, till 31/12/2025! Following a first phase, whose results have been shown on June 25^th in Tokyo (jointly with the ISFV21 and ISPIV2025 conferences), it has been decided to extend the challenge until the end of year 2025. Please feel free to submit (or replace) your result for case 1 (turbulent channel flow, influence of time step), case 2 (turbulent boundary layer in cylinder wake, influence of seeding density and setup geometry) and case 3 (experimental Rayleigh-Bénard convection, influence of seeding density)! Please note that, for your results to be included in the forthcoming publication, results should be submitted for case 3, and at least one of the other cases. Results obtained by teams who participated to the first phase are published on this portal; for a more detailed analysis, slides presented during the Tokyo workhop are also available for download!

• First LPT and DA challenge, held in 2020. Go to the pages for the  LPT and DA cases to have more information on the data and submit your result!

Citation

When referring to the portal in your published or communicated work, please cite

Leclaire, B., Cornic, P., Champagnat, F., Fabre, E., & Calmels, F. (2022). A web portal for automatic performance evaluation of Lagrangian Particle Tracking and Data Assimilation algorithms. In 20th International Symposium on the Application of Laser and Imaging Techniques to Fluid Mechanics, Lisbon, Portugal.

Additionally, to refer to a specific dataset, please cite

• 1^st LPT Challenge: Sciacchitano, A., Leclaire, B., & Schroeder, A. (2021). Main results of the first lagrangian particle tracking challenge. In Proceedings of 14th International Symposium on Particle Image Velocimetry (Vol. 1, No. 1, pp. 1-14). ILLINOIS Tech/Paul V. Galvin Library.
• 1^st DA Challenge: Sciacchitano, A., Leclaire, B., & Schroeder, A. (2021). Main results of the first data assimilation challenge. In Proceedings of 14th international symposium on particle image velocimetry (Vol. 1, No. 1, pp. 1-13). ILLINOIS Tech/Paul V. Galvin Library.

News

17.09.2025. LPT Challenge still running, till end of 2025! Using the portal, you are welcome to submit a result (or replace an existing one) for any of the LPT cases of the 2nd challenge, until 31/12/2025! Results submitted by this date will be considered for the upcoming journal publication. Submission will be still possible past this date, but results will not be enclosed in the article. Please note that, for your results to be included in the forthcoming publication, results should be submitted for case 3, and at least one of the other cases.

13.04.2025. Submission deadline of the 2^nd LPT and DA Challenge extended! Following several requests, the due date for submitting results to the 2^nd LPT and DA Challenge has been extended to April 29^th.

07.04.2025. Result submission to the 2^nd LPT and DA Challenge now open! Please upload your results for the LPT and/or DA Challenge until April 15th (included)! For more information, please consult the cases' pages.

31.03.2025. Additional information regarding Case 3 of the 2^nd DA Challenge Case 3. Instructions of DA Case 3 pertaining to requested result have been completed.

14.03.2025. Upload forms of the 2^nd LPT and DA Challenge open for format checks! Participants to the Challenge now have the possibility to upload sample files for the LPT and/or DA Challenge, in order to check whether their result formatting is right. Files uploaded will not be evaluated, nor considered as an official submission to the challenge.

31.01.2025. Datasets of the 2^nd LPT and DA Challenge are released!

07.01.2025. Datasets of the 2^nd LPT and DA Challenge coming soon! Datasets will be released by 31^st of January. The due date for uploading results on this portal will be April 15^th. Comparative analysis of the results will be presented during a dedicated workshop on June 25^th in Tokyo, jointly with the ISFV21 and ISPIV2025 conferences.

11.07.2022. Opening of the portal in beta version, starting with the Two-Pulse case of the 1st LPT Challenge. For final debug purposes, evaluation is temporarily launched by a member of the developing team after a result has been uploaded. If you encounter problems or delays during your result submission, please contact us at flow-benchmarks@onera.fr.