221 Numerical modeling of flows in rough additive manufactured devices

Job title:

221 Numerical modeling of flows in rough additive manufactured devices

Company:

Centre National d’Etudes Spatiales

Job description

Recently, additive manufacturing (AM) has become one of the most used methods in the space industry to manufacture liquid propulsion engine parts. Some companies are considering in particular to use this process to produce 100% of their engine. However, this method of manufacturing causes performance problems linked to surface roughness, particularly in small diameter veins or in turbomachines.Moreover, the AM process can lead to micro-structured surface roughness, with peculiar privileged directions and size distributions. On the contrary, the available models that take into acount roughness in the formulation of wall laws for RANS turbulence models have been developped for random distributed (“sand-grained type”) roughness. The present models show poor predictive ability. Finally, for the application to turbomachines, the turbulent models and the wall laws that come together have to be adapted to take into account the high streamlines curvature and the effects of rotation.Therefore, complex and advanced models are necessary to be able to correctly predict the performances of these fluidic systems produced in AM.Established in 2020, the Laboratory of Fluid and Energy Systems Engineering (LIFSE – 202023534Y) is a joint research unit between the École Nationale Supérieures d’Arts et Métiers and Conservatoire National des Arts et Métiers. Its field of action ranges from fundamental research to applied research to meet the growing number of scientific and technological challenges. LIFSE also responds to the demands of the socio-economic world through national and European research programs or industrial research projects. The specificity of LIFSE lies in research that combines different disciplinary fields and approaches in order to design, analyze and improve the efficiency of innovative and environmentally friendly fluid and energy systems. LIFSE relies on the CONFLUENCE technological platform, providing high-tech equipment and simulation tools, some of which have advanced technological maturity levels (TRL higher than five).This activity is part of a global LIFSE/CNES project on the hydraulic impact of the roughness of parts obtained in AM. A first experimental study that uses the experimental means of the LIFSE is under development. This study will lead to an experimental database of friction factors and velocity profiles above AM and traditional sand-grained veins in the hydraulic loop of the LIFSE. This plates will be manufactured and the surfaces roughness will be characterized with the help of the PIMM laboratory of Arts et Métiers. This database will then be used in the PhD thesis as a benchmark for the models.The PhD thesis work will use an open-source Computational Fluid Dynamics solver (openFOAM) as a development framework and platform for adapted wall laws. The LIFSE also has an access to the HPC Cassiope Cluster of Arts et Metiers as a main contributor.During the PhD thesis, experimental studies on progressively more complex geometries are scheduled, from elbows to vaned diffusers with pre-rotators, in order to include progressively more realistic effects of rotation. This experimental counter-part will be done by research engineers and a professor, in collaboration with the PhD candidate.For more Information about the topics and the co-financial partner (found by the lab !); contact Directeur de thèse –Then, prepare a resume, a recent transcript and a reference letter from your M2 supervisor/ engineering school director and you will be ready to apply online before March 14th, 2025 Midnight Paris time !

Expected salary

Location

Paris

Job date

Wed, 05 Feb 2025 05:29:49 GMT

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