JAXA Supercomputer System Annual Report February 2025-January 2026

Report Number: R25EA2121

Subject Category: Aeronautical Technology

PDF (to be added)

• Responsible Representative: Sadatake Tomioka, Leader, Hydrogen Aerospace Plane Team
• Contact Information: Hideyuki Taguchi(taguchi.hideyuki@jaxa.jp(旧)、taghide@rs.tus.ac.jp(現))
• Members: Yu Endo, Chihiro Fujio, Kaito Hirose, Motoyuki Hongoh, Hiroki Itou, Taku Inoue, Ryota Kobayashi, Masafumi Momose, Toshihiko Munakata, Tomofumi Narita, Koutarou Nakayama, Shinji Nakaya, Shunsuke Takamatsu, Hideyuki Taguchi, Manawa Watanabe, Satoi Yamaguchi, Sawaka Yada

Abstract

This research aims at the demonstration of the thrust control method of a hypersonic pre-cooled turbojet engine using liquid hydrogen fuel and the aircraft / propulsion integrated control method. We acquire the control characteristics of the hypersonic integrated control experimental aircraft to establish the aircraft / propulsion integrated control method taking into account the mutual interference of hypersonic airframe and hypersonic engines. In addition to defining the required specifications of hypersonic aircraft, we present the design specifications of the hypersonic experimental aircraft for carrying out flight demonstration of hypersonic pre-cooled turbojet engine.

Reference URL

Please refer to https://www.ard.jaxa.jp/eng/research/hydrogenfuel/hydrogenfuel.html .

Reasons and benefits of using JAXA Supercomputer System

We need a long calcularion time to obtain the aerodynamic characteristics of the overall hypersonic experimental aircraft by CFD analyses.

For reacting flow simulation including NOx, there are many chemical species and calculation cost is high.

Achievements of the Year

A deep learning-based flow prediction model was constructed using a 2D combustion CFD dataset obtained with JSS3, and integrated design optimization of the hypersonic airbreather's airframe and propulsion system was performed using this model. CFD was performed for a selected optimum design of an airframe and a scramjet engine to evaluate its aerodynamic performance (Fig. 1).

For a double delta-wing reusable launch vehicle, low-speed aerodynamic analysis was performed using FaSTAR to investigate the effect of dihedral angle on static stability (Fig. 2).

A vortex generator was mounted on the intake ramp surface of a ramjet engine for High Mach Integrated Control Experiment (HIMICO), and its effect on the flow field inside the intake was investigated using CFD analysis (Fig. 3).

CFD simulations of the hydrogen jet flow inside the injector of a hydrogen gas turbine combustor were performed (Fig. 4).

Fig.1: Aerodynamic analysis for wedge-shaped waverider

Fig.2: Aerodynamic analysis for a double delta-wing reusable launch vehicle

Fig.3: Visualization of vortex structure and wall shear stress on the intake clamp surface.

Fig.4: CFD analysis of hydrogen jets inside a hydrogen gas turbine combustor

Publications

- Peer-reviewed papers

Yuki Kuwabara, Manami Fujii, Yuki Fujimori, Yusuke Hoshiya, Rintaro Tanaka, Shima Ariyoshi, Ayuto Suzuki, Tetsuya Sato, Hidemi Takahashi, Hideyuki Taguchi, Experimental and Numerical Investigation of the Sideslip Angle on the Ramjet Intake for High Mach Integrated Control Experiment (HIMICO) Model at Mach 2, Journal of Evolving Space Activities, 2025.

- Oral Presentations

C. Fujio and H. Taguchi, “Design exploration of hypersonic vehicle airframe and air-breathing engine using deep-learning flowfield prediction,” 4th International Conference on High-Speed Vehicle Science & Technology, Sept. 2025, Tours, France

Usage of JSS

Computational Information

• Process Parallelization Methods: MPI
• Thread Parallelization Methods: OpenMP
• Number of Processes: 1 - 2
• Elapsed Time per Case: 30 Hour(s)

JSS3 Resources Used

Fraction of Usage in Total Resources*1(%): 1.11

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