Acoustic Liner Program for High-bypass-ratio Aircraft engines (acoustic performance improvement)

JAXA Supercomputer System Annual Report February 2025-January 2026

Report Number: R25EDA101C75

Subject Category: Aeronautical Technology

Responsible Representative: Kenichiro Nagai, Aeronautical Technology Directorate, Aviation Environmental Sustainability Innovation Hub
Contact Information: Shunji ENOMOTO(enomoto.shunji@jaxa.jp)
Members: Shunji Enomoto

Abstract

Ultra high bypass ratio aviation jet engines have a smaller sound absorbing liner area than conventional engines. In this project, we will develop sound-absorbing device technology that provides high noise reduction performance even with a small-sized sound-absorbing liner.

Reference URL

N/A

Reasons and benefits of using JAXA Supercomputer System

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

Achievements of the Year

This study performs numerical simulations of phenomena occurring when sound is incident on an acoustic liner for aircraft jet engines. This year, we attempted to calculate the acoustic impedance of the acoustic liner when a grazing flow with M=0.1 to 0.3 exists in a flow duct equipped with the acoustic liner. Here, calculations were performed for cases such as when sound was incident from the upstream side (Fig. 1) and when sound was incident from the side of the acoustic liner cell (Fig. 2), using a shape simulating a single hole in the perforated plate element of the acoustic liner, with an airflow of M=0.1 present. From these results, a scattering matrix was calculated. Fig. 3 shows the acoustic impedance derived from this. The figure shows how the impedance changes compared to the case without grazing flow. While this year's work is still at the trial calculation stage and requires improved accuracy, it demonstrates the potential for calculating the impedance of acoustic liners through such numerical simulations.

Fig.1(video): Sound pressure when sound is incident from the upstream side

Fig.2(video): Sound pressure when sound is incident from the side of the acoustic liner cell

Fig.3: Acoustic impedance

Publications

- Non peer-reviewed papers

Numerical analysis of acoustic liners using transfer matrix method

JAXA-SP-25-010

https://jaxa.repo.nii.ac.jp/record/2002532/files/AA2530019005.pdf

Usage of JSS

Computational Information

Process Parallelization Methods: MPI
Thread Parallelization Methods: OpenMP
Number of Processes: 28
Elapsed Time per Case: 48 Hour(s)

JSS3 Resources Used

Fraction of Usage in Total Resources*1(%): 0.19

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	4881451.39	0.22
TOKI-ST	10965.90	0.01
TOKI-GP	0.00	0.00
TOKI-XM	0.00	0.00
TOKI-LM	0.00	0.00
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	10240.00	0.07
/ssd	30720.00	1.87

Archiver Resources
Archiver Name	Storage Used (TiB)	Fraction of Usage*2(%)
J-SPACE	16.31	0.05

*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)	171.21	0.12

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