IMT Lille Douai research center
Smartphone assisted flow imaging for research and education
Optical methods are an ever-developing tool of
experimental mechanics and provide information on
various types of flows (multiphase, granular, non-
Newtonian, turbulent...)[1]–[3]. Lately frugal developments
of optical methods have been proposed, based on the use
of smartphones[4], [5]. Camera performances of the latter
have indeed become comparable, to some extent, to those
of scientific cameras commonly used for flow imaging,
while staying relatively cheaper. Smartphone assisted flow
imaging thus shows great potential for research by making
some advanced methods affordable, and eventually offering an integration of the data acquisition and image processing chain to a single tool. Without seeking to replace advanced optical metrology, it provides fast, inexpensive, and flexible screening of physical phenomena, and quickly and easily identify key features. Using numerical science and advanced data processing, smartphone eventually offer new opportunities of flow imaging, in research projects for which conventional methods would not have been easily implemented. Beyond the metrological considerations, smartphone assisted imaging also provides great educational opportunities,
Figure 1: Rainbow PIV by Aguirre-Pablo et al. [4]
bringing together physical and numerical sciences, and being at the same time visual, intuitive, relatively inexpensive to implement. It opens the door to virtual, remote and adaptable practical works at all stages of study, the relevance of which has been emphasized by the COVID19 pandemic [6].
The aim of this project is to develop an experimental tool for Smartphone Assisted Flow Imaging for Research and Education (SAFIRE), synthetizing recent advances in the fields of optical methods for flow measurement and image analysis, and applicable for both frugal research and educational innovation.
The tasks of the research fellow will be to identify the potential of measurement techniques, develop the hardware and software for data acquisition and processing, and apply the designed system to research and teaching scenarios. Those include (but are not limited to): tomographic flow velocimetry and density measurement in complex flows, study of multiphase and granular flows, development of remote teaching methods and practical works. The method will contribute to research projects in energy efficienc y, environmental flows and civil engineering.

Person specification:
We are looking for an enthusiast candidate willing to conduct multidisciplinary cutting-edge research (and potentially engage in educational innovation projects). The ideal candidate is expected to have a PhD in physical or numerical sciences, engineering, or any related fields, (graduation complete at the project starting date). Strong analytical, organisation and communication skills, proven aptitude for experimental work are required, along with experience in one or several of the followings: Image analysis, optics, experimental (fluid) mechanics, programming (Matlab, C++, Python ...). Knowledge in optical methods for fluid mechanics (PIV, PLIF...) and experience with LabView and/or mobile app development would be a plus. This position is open to early career researchers (no prior postdoc experience required). The recruited candidate is expected to contribute to international scientific publications and communication, and can be asked to involve in teaching and supervision activities from graduate to post-graduate levels (supervision of lab courses, undergraduate and MSc student projects, PhD students). Eligibility to live and work in the EU is required.

[1] T. Lacassagne, S. Simoëns, M. E. Hajem, et J.-Y. Champagne, « Ratiometric, single-dye, pH-sensitive inhibited laser- induced fluorescence for the characterization of mixing and mass transfer », Exp. Fluids, vol. 59, no 1, p. 21, janv. 2018, doi: 10.1007/s00348-017-2475-y.
[2] J. Westerweel, G. E. Elsinga, et R. J. Adrian, « Particle Image Velocimetry for Complex and Turbulent Flows », Annu. Rev. Fluid Mech., vol. 45, no 1, p. 409‐436, 2013, doi: 10.1146/annurev-fluid-120710-101204.
[3] S. Hamidouche, J. V. Simo Tala, et S. Russeil, « Analysis of flow characteristics downstream delta-winglet vortex generator using stereoscopic particle image velocimetry for laminar, transitional, and turbulent channel flow regimes », Phys. Fluids, vol. 32, no 5, p. 054105, mai 2020, doi: 10.1063/5.0005788.
[4] A. A. Aguirre-Pablo, M. K. Alarfaj, E. Q. Li, J. F. Hernández-Sánchez, et S. T. Thoroddsen, « Tomographic Particle Image Velocimetry using Smartphones and Colored Shadows », Sci. Rep., vol. 7, no 1, p. 1‐18, juin 2017, doi: 10.1038/s41598-017-03722-9.
[5] K. Hayasaka et Y. Tagawa, « Mobile visualization of density fields using smartphone background-oriented schlieren », Exp. Fluids, vol. 60, no 11, p. 171, oct. 2019, doi: 10.1007/s00348-019-2817-z.
[6] « Smartphonique.fr – Utilisation du smartphone en sciences. » https://smartphonique.fr/?lang=fr (consulté le janv. 12, 2021).