本文へ移動

サイトナビゲーションへ移動

検索ボックスへ移動

サイドバーへ移動

ここは、本文エリアの先頭です。

Study on understanding regolith scattering phenomena by thruster plume

JAXA Supercomputer System Annual Report February 2021-January 2022

Report Number: R21EEU30200

Subject Category: Space and Astronautical Science

PDF available here

  • Responsible Representative: Mitsuhisa Baba, Researcher, Japan Aerospace eXploration Agency, Research and Development Directorate, Rearch Unit II
  • Contact Information: Mitsuhisa Baba(baba.mitsuhisa@jaxa.jp)
  • Members: Mitsuhisa Baba

Abstract

As observed during the touchdown of Hayabusa2 and OSIRIS-REx, regolith is scattered by thruster operation during takeoff on low-gravity objects. Understanding the phenomenon is important first because it will affect mission and spacecraft design for future space science and exploration. Microgravity experiments using a drop tower have been conducted for this study, but there are strong constraints on the duration of microgravity and the size of the experimental setup that can be used. Numerical calculations are therefore needed.

Reference URL

N/A

Reasons and benefits of using JAXA Supercomputer System

A coupled CFD and DEM analysis is effective for understanding this phenomenon, but the cost of this calculation is generally significant. Therefore, a super computer such as JSS3 is important tool for this study.

Achievements of the Year

The CFD-DEM analysis software, scFLOW, was tested. The license server was provided by ourselves and was referenced from JSS3 to run the analysis. A parallelization test analysis was also conducted using simple test analysis data to confirm the parallelization efficiency.

Publications

N/A

Usage of JSS

Computational Information

  • Process Parallelization Methods: MPI
  • Thread Parallelization Methods: OpenMP
  • Number of Processes: 16 – 36
  • Elapsed Time per Case: 5 Minute(s)

JSS3 Resources Used

 

Fraction of Usage in Total Resources*1(%): 0.00

 

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 2.93 0.00
TOKI-ST 271.99 0.00
TOKI-GP 0.00 0.00
TOKI-XM 0.00 0.00
TOKI-LM 0.00 0.00
TOKI-TST 864.02 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 50.00 0.05
/data and /data2 250.00 0.00
/ssd 250.00 0.06

 

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

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

JAXA Supercomputer System Annual Report February 2021-January 2022