Periodic Reporting for period 2 - STREAM (Simulation of Turbulence and RoughnEss in Additive Manufactured parts)
Período documentado: 2021-04-01 hasta 2022-09-30
These results were mainly disseminated through publications (Journal of Turbomachinery), participation to international conferences (ASME 2022, ETMM13, FFHMT22) and training courses (VKI lecture series). The exploitation of these results will be done through software patent (YALES2) and following projects focused on the modelling and design of additively manufactured heat exchangers for the new generation of aero-engines.
1. Definition of the predominant physical parameters impacting the predictive character of CFD simulations => achieved
2. Assessment of the existing wall models to predict pressure loss and heat flux for heat exchangers simulations for both RANS and LES approaches => achieved
3. Improvement of wall models to consider both roughness and complex geometries effects => achieved
4. Development of a roughness structure and mesh generation tool for numerical LES-RANS benchmarks => achieved and integrated in YALES2 code
5. Optimization of the architecture of the exchanger regarding the objective of dimensioning => achieved with a dedicated methodology
6. Local optimization of the flow and heat transfer considering the orientation of the walls, and therefore their roughness => partially achieved as optimization is not local yet
7. Adaptation of the physical model to the type of heat exchanger => not needed in the STREAM configurations
Beyond to these expected outcomes, the STREAM project results had a greater impact, which has led to new projects, new collaborations and new topics in line with STREAM:
– 2022-2025, NEMO project (TEMISTH, IRT M2P) funded by PIA (Plan d’Investissement d’Avenir) in France: investigation of post-processing techniques on performances of heat exchangers.
– 2021-2024, WINGS project (CENAERO, VKI, SAFRAN AEROBOOSTERS) funded by Belgium: design and modeling of additively manufactured heat exchangers. This project will build upon the STREAM results to perform the design of heat exchangers in the framework of the development of the new RISE engine.
– 2023-2028, YALES2-AE project (CORIA/SAFRAN/GDTECH) funded by SAFRAN: this project is focused on the industrialization of the YALES2 software for aeronautical applications.
– SAFRAN TECH & SAFRAN AEROBOOSTER contacted CORIA for the modeling of sub- and super-critical heat exchangers.
– TOTAL ENERGIES has started a collaboration in 2022 with both CNRS-CORIA and TEMISTH on heat exchangers.
Additional perspectives can also be drawn from the STREAM project and pave the way for future projects:
– The STREAM project has been subjected to the same difficulties encountered by experts in accurately approaching & quantifying additive manufacturing roughness despite the fact that key parameters have been identified. More effort should be put on the characterization and quantification of additive manufacturing roughness.
– The STREAM project has also shown that existing correlations for the friction factor and for the Nusselt number can be used on some narrow validity range especially for pressure losses. Correlations for Nusselt number are far less reliable. New projects should focus on building new databases and new correlations for these heat exchangers.
– The STREAM project has clearly highlighted the very high impact of the printing direction on the friction factor and Nusselt number. This dependency is directly expressed by very different Effective Slope while having the same other roughness parameters. This flow direction sensitivity can lead to different impacts of the roughness on different parts of a heat exchanger and it has to be taken into account. This issue is linked to local optimization, which is not yet possible in current tools.