MEXT Program for Promoting Researches on the Supercomputer Fugaku, Leading research on innovative aircraft design technologies to replace flight test

JAXA Supercomputer System Annual Report February 2025-January 2026

Report Number: R25ECMP30

Subject Category: Competitive Funding

Responsible Representative: Yuko Inatomi, Institute of Space and Astronautical Science, Department of Interdisciplinary Space Science
Contact Information: Ryoji Takaki(takaki.ryoji@jaxa.jp)
Members: Ryoji Takaki

Abstract

Realization of high-precision aerodynamic prediction by high-fedelity LES analysis around whole aircraft configulation for actual flight conditions.

Reference URL

Please refer to http://www.klab.mech.tohoku.ac.jp/fugaku/index.html .

Reasons and benefits of using JAXA Supercomputer System

It is possible to develop programs efficiently because JSS has the same architecture as the final target "Supercomputer Fugaku",

Achievements of the Year

The Cartesian grid method currently in use enables fully automatic generation of computational grids, making the handling of moving and deforming objects easier compared to conventional methods. Following last year's efforts, we attempted its application to three-dimensional moving and deforming objects. Figure 1 shows an analysis example of an aircraft landing gear retraction and extension. We confirmed the feasibility of analyzing moving objects with complex geometries. Furthermore, we performed practical analyses on complex shapes.

Fig.1: Example of analysis of flow around a 3D moving object (loading/unloading of landing gear)

Publications

- Oral Presentations

Ryoji Takaki, "Development of a Method for Analyzing Flow Around Three-Dimensional Moving Objects Using Cartesian Grids and the Embedded Boundary Method," 57th Fluid Mechanics Symposium / 43rd Aerospace Numerical Simulation Technology Symposium, 3B06, July 4, 2025.

Ryoji Takaki, "Development of a Fluid Analysis Method Using Fully Automatic Computational Grid Generation," 2025 Aerospace Aerodynamics and Design Research Meeting, October 4, 2025.

Ryoji Takaki, "Integration and Visualization of Surface Physical Quantities in the Embedded Boundary Method," 39th Symposium on Computational Fluid Dynamics, OS2-4-4-04, December 16, 2025.

Usage of JSS

Computational Information

Process Parallelization Methods: MPI
Thread Parallelization Methods: OpenMP
Number of Processes: 1 - 240
Elapsed Time per Case: 500 Hour(s)

JSS3 Resources Used

Fraction of Usage in Total Resources*1(%): 1.25

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	33595489.00	1.52
TOKI-ST	43245.17	0.04
TOKI-GP	2589.75	0.04
TOKI-XM	0.00	0.00
TOKI-LM	58.68	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	0.00	0.00
/ssd	0.00	0.00

Archiver Resources
Archiver Name	Storage Used (TiB)	Fraction of Usage*2(%)
J-SPACE	2.59	0.01

*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)	9.53	0.01

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