JAXA Supercomputer System Annual Report April 2018-March 2019

Report Number: R18EA0716

Subject Category: Aeronautical Technology

PDF available here

• Responsible Representative: Toshio Nishizawa, Aeronautical Technology Directorate, Propulsion Research Unit
• Contact Information: Shunji ENOMOTO(enomoto.shunji@jaxa.jp)
• Members: Shunji Enomoto, Kae Ito, Tatsuya Ishii

Abstract

Noise generated from a jet engine is dominant to total aircraft noise level and it is very important to reduce this. In this project, demonstration of exhaust noise reduction by changing exhaust duct shape, and study of noise reduction technique by numerical analysis were carried out.

Reference URL

Please refer to ‘Green engine technology | ECAT – Environment-Conscious Aircraft Technology Program | Aeronautical Technology Directorate‘.

Reasons for using JSS2

The calculation was LES with a large amount of computation and storage usage. It was necessary to use SORA-PP and SORA-FS.

Achievements of the Year

In order to investigate the behavior of sound waves passing through a jet, LES calculation of the jet was performed using UPACS-LES. The incident sound wave travels across the jet. In this year, to approximate the experimental shape, a rectangular jet was calculated. Figure 1 shows the iso-Mach number plane of the jet. Fig. 2 shows the sound pressure distribution of the cross section. Reflection and shielding of incident sound occurred in the jet downstream direction. Fig. 3 shows the phase of the incident sound. As the sound passes through a jet, the wavefront is slightly flowing downstream.

Fig.1: Iso Mach number surface and speaker position of the rectangular jet

Fig.2: Sound pressure level of sound emitted from the speaker

Fig.3: Phase of sound emitted from the speaker

Publications

– Non peer-reviewed papers

Kae Ito, Tatsuya Ishikawa, Jin Ishikawa, “Experimental study on high frequency sound shielding by jet”, S0510405, The Accual meeting 2018, The Japan Society of Mechanical Engineers

Usage of JSS2

Computational Information

• Process Parallelization Methods: MPI
• Thread Parallelization Methods: OpenMP
• Number of Processes: 60
• Elapsed Time per Case: 10 Hour(s)

Resources Used

Fraction of Usage in Total Resources*1(%): 0.32

Details

Please refer to System Configuration of JSS2 for the system configuration and major specifications of JSS2.

*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.

JAXA Supercomputer System Annual Report April 2018-March 2019