JAXA Supercomputer System Annual Report February 2025-January 2026

Report Number: R25EA3800

Subject Category: Aeronautical Technology

PDF (to be added)

• Responsible Representative: Yoshikazu Makino, Aviation Technology Directorate, Re-BooT Project Team
• Contact Information: Hiroaki Ishikawa(ishikawa.hiroaki2@jaxa.jp)
• Members: Junichi Akatsuka, Hiroaki Ishikawa, Shinya Koganezawa, Masashi Kanamori, Satoshi Kondo, Ryo Shimada, Hajime Miki, Yusuke Naka, Atsushi Shinozuka, Kensuke Soneda, Hisato Takeda, Atsushi Ueno, Tatsunori Yuhara, Riki Matsuyama

Abstract

It is important to acquire world-class high level technology in order to enhance the international competitiveness of Japan's aircraft manufacturing industry, especially for supersonic transport. In addition, the advantage is great, such as revitalizing economic activities from the business and tourism aspects by shortening the travel time of supersonic flight, and the health aspects of passengers such as suppression of economy class syndrome. Based on this, the purpose of this project is to acquire the key technologies required to realize a "quiet supersonic aircraft" and contribute to the development of the aircraft manufacturing industry and air transport in the future. In this project, R&D on sonic boom estimation, measurement and evaluation technologies will contribute to the formulation of international standards at ICAO required for over land supersonic flight. The integrated design technology that simultaneously satisfies both low boom, low drag, low noise and weight reduction are developed to present a concept of a supersonic transport that simultaneously satisfies these technical goals.

Reference URL

Please refer to https://www.aero.jaxa.jp/eng/research/frontier/sst/ .

Reasons and benefits of using JAXA Supercomputer System

To develop a future supersonic transport that satisfies the requirement of low sonic-boom and low aerodynamic drag, it is necessary to estimate aerodynamic properties and sonic-boom properties by accurate numerical simulation. JSS is used to estimate aerodynamic performances of various configurations with high accuracy and high efficiency for the designing of the low-boom supersonic transport.

Achievements of the Year

The design methods for reducing sonic boom can be broadly divided into two approaches. The first is an inverse-design approach, in which a target equivalent area distribution is defined, and the aircraft shape is iteratively modified so that its equivalent area distribution approaches that target. The second is a direct-design approach, in which an optimal configuration is explored within a predefined design space using optimization methods to minimize the boom intensity.

In JAXA's low-boom design, the inverse-design approach is applied to reduce the front boom, while the direct-design approach is primarily applied to reduce the rear boom. Specifically, the front boom is reduced by inverse-designing the fuselage shape such that its equivalent cross-sectional area distribution becomes an ideal distribution. The rear boom is minimized by directly optimizing the aircraft configuration in the rear region using a surrogate model.

For rear-boom reduction, a method was proposed that utilizes the forward Mach cone to define an effective design space during the formulation of the optimization problem. This method was applied to an aircraft configuration with a maximum boom intensity of approximately 96 dB, and by reducing both the front and rear booms, an overall reduction of about 10 dB was achieved. The results of these studies were reported at the 63rd Aircraft Symposium of the Japan Society for Aeronautical and Space Sciences.

Fig.1: Near-field CFD analysis

Fig.2: Effect of applying a low-boom design method to the initial shape

Publications

- Non peer-reviewed papers

Ueno, A. and Makino, Y.: Off-track robust low-boom design for NASA/Boeing N+2 concept model, 63rd Aircraft Symposium, 2025.

Usage of JSS

Computational Information

• Process Parallelization Methods: MPI
• Thread Parallelization Methods: Automatic Parallelization
• Number of Processes: 960 - 3840
• Elapsed Time per Case: 100 Hour(s)

JSS3 Resources Used

Fraction of Usage in Total Resources*1(%): 2.20

Details

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

*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

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

JAXA Supercomputer System Annual Report February 2025-January 2026