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Study of high speed fluid dynamics

JAXA Supercomputer System Annual Report February 2023-January 2024

Report Number: R23EU0902

Subject Category: Space and Astronautical Science

PDF available here

  • Responsible Representative: Akira Oyama, Professor, Institute of Space and Astronautical Science, JAXA
  • Contact Information: oyama.akira@jaxa.jp(oyama.akira@jaxa.jp)
  • Members: Sakura Endo, Kento Kaneko, Naruhiko Nimura, Shu Ota, Akira Oyama, Ryutaro Onishi, Ken Sawada, Atsushi Shinozuka, Masayuki Sasaki, Satoshi Sekimoto, Yukito Tsunoda

Abstract

To conduct fundamental research on high-speed fluid dynamics such as aerodynamic design of Mars drones

Reference URL

N/A

Reasons and benefits of using JAXA Supercomputer System

High-fidelity flow simulations such as the large eddy simulations are required to analyze Mars drones.

Achievements of the Year

A CFD analysis was performed to investigate the effect of the center of gravity position on the dynamic instability of the Hayabusa type capsule during subsonic flight (Fig. 1). The results show that the capsule loses dynamic stability as the center of gravity moves rearwards. They also show that the front of the capsule contributes to dynamic stability and the rear part of the capsule contribute to dynamic instability respectively .

Numerical fluid dynamics simulations were also conducted around the coaxial exhaust nozzle of an air-assisted sounding rocket in order to clarify how the interference between multiple jets from the nozzle affects the thrust (Fig. 2). The results showed that the thrust generated by the nozzle was reduced by 1.15% at flight altitudes where the rocket engine is overexpanded due to the interference effect of the jets.

Annual Reoprt Figures for 2023

Fig.1: Streamlines around the capsule (coloured by velocity in the main flow direction)

 

Annual Reoprt Figures for 2023

Fig.2: Flow field around the nozzle

 

Publications

– Oral Presentations

Sakura Endo, Akira Oyama and Kazuhiko Yamada, ”Numerical Study on Dynamic Instability of Reentry Capsule at Subsonic Speeds,”8-12 January 2024AIAA SCITECH 2024 Forum, https://doi.org/10.2514/6.2024-2866, January 2024.

Usage of JSS

Computational Information

  • Process Parallelization Methods: MPI
  • Thread Parallelization Methods: Automatic Parallelization
  • Number of Processes: 57
  • Elapsed Time per Case: 60 Hour(s)

JSS3 Resources Used

 

Fraction of Usage in Total Resources*1(%): 1.33

 

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 31567168.16 1.43
TOKI-ST 1300135.72 1.40
TOKI-GP 17.11 0.00
TOKI-XM 0.00 0.00
TOKI-LM 2137.42 0.16
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 1592.50 1.32
/data and /data2 159365.00 0.98
/ssd 12550.00 1.19

 

Archiver Resources
Archiver Name Storage Used
(TiB)
Fraction of Usage*2(%)
J-SPACE 0.08 0.00

*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)
1447.78 0.65

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

JAXA Supercomputer System Annual Report February 2023-January 2024