Periodic Reporting for period 3 - AMICAL (Advanced Modeling CapabiLities For UHBR Low Noise Fan Technology)
Reporting period: 2023-07-01 to 2023-12-31
The methods and maturity of computational environments when targeting high-fidelity aero-acoustic simulations on industrial turbomachinery cases were improved. High-fidelity aero-acoustic simulations were performed using the Fidelity flow environment. This includes the addition of the FW-H propagation module in Fidelity, for both time-domain and frequency-domain formulation and the implementation of the acoustic liner in the high-fidelity CharLES flow solver. Many developments were made in the LBM solver ProLB including improved boundary conditions and best practices. One of the first high-fidelity LB simulations of a fan/OGV module with external domain in the high subsonic régime was carried out, producing good results. The technique for in-duct noise source identification from CFD results was improved significantly. By including the CFD-calculated average flow in the acoustic post-processing, detailed noise sources could be visualised, even on the rotor. Several successful applications were done on NLH/LBM calculations on realistic UHBR configurations. Post-processing techniques were made ready for application outside the engine duct, by which in-duct noise sources can be related to far-field noise, leading to a major step into understanding the origin of UHBR fan noise.
CERFACS: the work includes the implementation and validation of the MRF algorithm to extend the compressible LBM solver to rotating configurations, the enhancement of the solver isotropy property by developing new LBM scheme based on different equilibrium and lattice, the aerodynamic simulation of a NASA-STD turbofan engine scaled at 1:5 and the analysis of the best suited compressible porous numerical model, including theoretical analysis, implementation strategy and development of a test model. An aerodynamic validation of the LB compressible solver on the ECL5 test case was performed, including development of best practices and improvements to the wall treatment. The compressible porous numerical model was tested for a grazing impedance tube. The work was then centered around the extension of the domain to include the external area around the fan/OGV module for the purpose of evaluating acoustic propagation, and on further improvements to the LBM compressible solver. One of the major outcomes of this project is the enhancement of the ProLB (LBM) solver, enabling it to perform aeroacoustics simulations on rotating machinery. These advancements can be immediately utilized within SAE which used this solver, leading to more accurate and efficient simulations. Additionally, all the developed results have been shared with the broader LBM scientific and industrial community.
PSA3: for the determination and characterization of acoustic sources in the fan/OGV region, a new efficient and fast beamforming method was developed, based on the acoustic pressure, the flow speed vector and the temperature in a set of sensor points within the computation domain. The method was successfully applied to numerical results with Cadence NLH method and CERFACS LBM software on the ECL5 geometry and to LBM calculations by SAE on an installed UHBR configuration. The method was presented to the Aeroacoustics community at the CEAS/AIAA Aeroacoustics Conferences of 2023 and 2024. Further dissemination is foreseen at a DNW/Safran workshop. Safran expressed their interest for future numerical studies on UHBR geometries.
The work proposed in this project will be applied to UHBR Fan/OGV integrated systems to study aeroacoustic and establish tone and broadband noise. The methodology and the tools proposed (mainly based on Large Eddy Simulation) are already validated on first labs test cases (TRL4). This project will give the opportunity to go further and to adapt and validate the high-fidelity technologies on more representative configurations up to TRL5. This proposal will accelerate the maturation of advance aeroacoustic tools and new low noise design fan module capacity toward TRL6 ; By helping to characterize the tones and broadband noise with high degree of reliability (including environment and technological effects), AMICAL will thus contribute to aeroacoustic performance and noise emission assessments of next UHBR installed large scale test (TRL5) and demonstrator (TRL6) planned in Clean Sky 2.