Liquid-Propellant Propulsion System Simulation

JAXA Supercomputer System Annual Report February 2025-January 2026

Report Number: R25EG3215

Subject Category: Research and Development

Responsible Representative: Taro Shimizu, Research and Development Directorate, Research Unit III
Contact Information: Hiedyo Negishi(negishi.hideyo@jaxa.jp)
Members: Ashvin Hosangadi, Yu Daimon, Taroh Fukuda, Osamu Fukasawa, Hideyo Negishi, Takenori Nakajima, Shinji Ohno, Masashi Toyama, Satoshi Ukai, Himeko Yamamoto, Rika Yamada, Andrea Zambon

Abstract

There is a strong demand for system-level simulation technologies that enable rapid evaluation of subsystems involving thermal-fluid dynamics in the field of space development. Utilizing 3D numerical simulation results of the space thermal-fluid system, component models are developed for the system analysis. The system analysis will use for evaluation of the development and operation for liquid rocket or spacecraft.

Reference URL

N/A

Reasons and benefits of using JAXA Supercomputer System

Component models of space thermal-fluid systems are conventionally very simple and sometimes not consistent with physics of fluid dynamis. However, because of the recent development of computer science, even computationally expensive models can be used for numerical analysis for designs. In addition, high-fidelity CFD clarified physical phenomena in the component, and it enhances to develop more accurate component models. Concequently, high-fidelity CFD analyses are essential to clarify the phenomena in the space thermal-fluid systems. JSS enables us to carry out trade-off studies with a wide range of parameter, which contribute to build new models and find out new insights of space thermal-fluid systems.

Achievements of the Year

With regard to JAXA projects such as MMX, HTV-X, G-HAB evaluation of design and risks, studies for improvement as well as understanding physical phenomena were carried out by making full use of the simulation technology of Reserch Unit III and JSS3.

Publications

N/A

Usage of JSS

Computational Information

Process Parallelization Methods: MPI
Thread Parallelization Methods: OpenMP
Number of Processes: 1440
Elapsed Time per Case: 146 Hour(s)

JSS3 Resources Used

Fraction of Usage in Total Resources*1(%): 0.90

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	22542479.76	1.02
TOKI-ST	372241.99	0.39
TOKI-GP	0.00	0.00
TOKI-XM	48.09	0.02
TOKI-LM	142.56	0.01
TOKI-TST	983.28	0.02
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	128000.00	0.84
/ssd	0.00	0.00

Archiver Resources
Archiver Name	Storage Used (TiB)	Fraction of Usage*2(%)
J-SPACE	36.42	0.11

*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)	2346.91	1.64

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