JAXA Special Publication JAXA-SP-19-003E

Development of High-fidelity Re-entry Safety Analysis Methods
Report Number: R18EG3216
Subject Category: Research and Development
URL: https://www.jss.jaxa.jp/en/ar/e2018/9147/
Responsible Representative
Eiji Sima, Research and Development Directorate, Research Unit III
Contact Information
Keiichiro Fujimoto (fujimoto.keiichiro@jaxa.jp)
Members
Taisuke Nambu, Takayuki Ito, Hideyo Negishi, Yoichi Ohnishi, Miki Nishimoto, Yu Daimon, Ashvin Hosangadi,
Masaaki Ino, Osamu Fukasawa, Shinji Ohno, Andrea Zambon, Takenori Nakajima, Takashi Amemiya, Yutaka
Umemura, Hironori Fujiwara, Hiroumi Tani, Keiichiro Fujimoto, Tetsufumi Ohmaru, Akiko Kotani, Taroh Fukuda,Mayu Matsumoto, Masashi Toyama, Shohta Sutoh, Akimitsu Terunuma, Kota Akai
Abstract
High-fidelity re-entry safety analysis code LS-DARC is under the development in JAXA in order to realize theaccurate EC predictions and the design-for-demise for the rocket upper statges and space-crafts. 6 Dof trajectory
analysis, aerodynamics, heat flux, 3D thermal conductance can be considered by the coupling analysis code basedon the reduced order models. Since models in LS-DARC is versatile and its turn-around time is very short, it has
been applied wide range of aerospace engineering applications such as the research and development activities forthe small re-entry capsule installed in HTV and the fly-back re-usable rocket.
Reasons for using JSS2
Probabilistic re-entry safety analysis based on the multi disciplinary coupling analysis with considering various
uncertainty factors is essential. In addition consideration on the design parameter effect should also be considered.
In addition, in-house computational environment is essential also for security reason. Consequently, JSS2 isessential.
Achievements of the YearIn this fiscal year, CFD analysis required to validate the heat flux and aerodynamic characteristics reduction
model has been conducted for the LS-DARC development. For the integrated validation of the LS-DARC, thepractical re-entry safety analysis has been conducted for the actual HIIB upper stage. As a result, accuracy
improvement needs were found for the accurate EC predictions. In addition, analysis tourn-around time has beenremarkably reduced, which is essential for the practical use. Schematic overview of models of LS-DARC and theexample results of the surface heat flux is shown as Fig. 1.

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JAXA Supercomputer System Annual Report (April 2018-March 2019)

Fig. 1: Schematic overview of the multi-disciplinary high-fidelity re-entry analysis
code LS-DARC, and surface heat flux distributions for HIIB upper stage

Publications- Peer-reviewed papers
Fujimoto, K., Tani, H., Negishi, H., Saito, Y., Iizuka, N., Okita, K., Kato, A., “Uncertainty Quantification forDestructive Re-Entry Risk Analysis: JAXA Perspective,” Stardust Final Conference, Conference, Springer book,
pp.283-300, 2018.
- Non peer-reviewed papers
Keiichiro Fujimoto, Hideyo Negishi, Nobuyuki Iizuka, Yasuhiro Saito, Koichi Okita,“Quantitative Risk Analysis for Reliability and Safety issues in Aerospace Engineering,” Safety Engineering
Symposium 2018, 2018.
Keiichiro Fujimoto, Hideyo Negishi, Ryo Nakamura, Yasuhide Watanabe, Toshiaki Daibo, Koichi Okita, “CFD
Research Needs for Re-entry Capsule Thermo-aerodynamics and Re-entry Safety Analysis,” 32nd CFD
Symposium, 2018.
Keiichiro Fujimoto, Hideyo Negishi, Toshiaki Daibo, Nobuyuki Iizuka, Ryuzo Shimizu, Koichi Okita (JAXA),“Development of High Fidelity Model-based Re-entry Safety Analysis Tool LS-DARC - Part 1,” 8th Space Debris
Workshop, 2018.
Usage of JSS2


Computational Information
Process Parallelization Methods

MPI

Thread Parallelization Methods

FLAT 並列

Number of Processes

96 - 512

Elapsed Time per Case

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JAXA Special Publication JAXA-SP-19-003E

Resources Used
Fraction of Usage in Total Resources*1 (%): 0.27
Details
Computational Resources
System Name

Amount of Core Time(core x hours)

Fraction of Usage*2 (%)

SORA-MA

2,324,723.64

0.28

SORA-PP106.380.00

SORA-LM

0.00

0.00

SORA-TPP

401.030.03

File System Resources
File System Name

Storage Assigned (GiB)

Fraction of Usage*2 (%)/home

426.01

0.44/data

25,939.49

0.46/ltmp

15,598.34

1.34

Archiver Resources
Archiver Name

Storage Used (TiB)

J-SPACE

Fraction of Usage*2 (%)
0.31

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.

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This document is provided by JAXA.