Acoustic Liner Program for High-bypass-ratio Aircraft engines

JAXA Supercomputer System Annual Report February 2025-January 2026

Report Number: R25EDA101P00

Subject Category: Aeronautical Technology

Responsible Representative: Kenichiro Nagai, Aeronautical Technology Directorate, Aviation Environmental Sustainability Innovation Hub
Contact Information: Junichi Oki(oki.junichi@jaxa.jp)
Members: Junichi Oki, Yousuke Fuyama, Shunji Enomoto, Hideaki Matsuura, Haruyuki Kato, Daisuke Sasaki

Abstract

In future high-bypass-ratio aircraft engines, surface area of acoustic lining will be smaller than in conventional engines. Our research aims to develop device technologies that achieve high acoustic performance and low aerodynamic drag, even with compact acoustic-liner configurations.

Reference URL

Please refer to https://www.aero.jaxa.jp/research/ecat/alpha/ .

Reasons and benefits of using JAXA Supercomputer System

To perform many LES calculations by changing the shape of the acoustic liner, the calculation performance and the storage capacity of JAXA supercomputer system were required.

Achievements of the Year

Acoustic liners are thin, two-layer structures consisting of a perforated facesheet and an underlying honeycomb core. They are installed on the inner walls of aircraft engines to decrease fan noise. However, the surface perforations disturb the grazing flow, potentially causing pressure loss and increased aerodynamic drag. In this study, the objective was to clarify how the aerodynamic characteristics of acoustic liners change under pressure fluctuations. Three-dimensional numerical simulations were conducted for a conventional round orifice (Round) and a proposed rectangular orifice with its short side aligned in the streamwise direction (Z-slit) under turbulent flow conditions with imposed pressure fluctuations simulating acoustic waves. Based on the simulation results, the distributions of shear stress and vortex structures near the orifice were visualized to evaluate their impact on aerodynamic performance. The distributions of shear stress near the orifice are shown in Figs. 1 and 2. The shear stress on the orifice surface was evaluated from the Reynolds stress, while that on the wall near the orifice was calculated using Newton's law of viscosity. The results indicate that the loss induced by shear stress on the orifice surface is dominant compared with that on the adjacent wall. The vortex structures are presented in Figs. 3 and 4. For the Z-slit orifice, which exhibits smaller loss, the development of vortical structures is suppressed, indicating reduced turbulence intensity.

Fig.1: The distribution of shear stress around orifice for Round

Fig.2: The distribution of shear stress around orifice for Z-slit

Fig.3(video): Inflow visualization using Q-Criterion isosurface for Round

Fig.4(video): Inflow visualization using Q-Criterion isosurface for Z-slit

Publications

- Oral Presentations

Hideaki Matsuura, Daisuke Sasaki, Shunji Enomoto, Junichi Oki, and Tatsuya Ishii, The effect of sound pressure on acoustic liner under three-dimensional turbulent flow and validation of the analysis method, 53rd Gas Turbine Society of Japan Annual Conference, (2025-10-08). (In Japanese)

Hideaki Matsuura, Daisuke Sasaki, Shunji Enomoto, and Junichi Oki, Flow structures and drag characteristics of slit-type acoustic liner model using large-eddy simulation, 2025 Asia-Pacific International Symposium on Aerospace Technology (APISAT2025), (2025-10-28).

Usage of JSS

Computational Information

Process Parallelization Methods: MPI
Thread Parallelization Methods: OpenMP
Number of Processes: 128 - 140
Elapsed Time per Case: 120 Hour(s)

JSS3 Resources Used

Fraction of Usage in Total Resources*1(%): 0.53

Details

Please refer to System Configuration of JSS3 for the system configuration and major specifications of JSS3.

Computational Resources
System Name	CPU Resources Used (Core x Hours)	Fraction of Usage*2(%)
TOKI-SORA	13645339.13	0.62
TOKI-ST	28455.32	0.03
TOKI-GP	0.00	0.00
TOKI-XM	0.00	0.00
TOKI-LM	2851.26	0.21
TOKI-TST	0.00	0.00
TOKI-TGP	0.00	0.00
TOKI-TLM	0.00	0.00

File System Resources
File System Name	Storage Assigned (GiB)	Fraction of Usage*2(%)
/home	0.00	0.00
/data and /data2	102400.00	0.67
/ssd	30720.00	1.87

Archiver Resources
Archiver Name	Storage Used (TiB)	Fraction of Usage*2(%)
J-SPACE	128.51	0.39

*1: Fraction of Usage in Total Resources: Weighted average of three resource types (Computing, File System, and Archiver).

*2: Fraction of Usage：Percentage of usage relative to each resource used in one year.

ISV Software Licenses Used

ISV Software Licenses Resources
	ISV Software Licenses Used (Hours)	Fraction of Usage*2(%)
ISV Software Licenses (Total)	576.67	0.40

*2: Fraction of Usage：Percentage of usage relative to each resource used in one year.