JAXA Supercomputer System Annual Report April 2018-March 2019

Report Number: R18EACA01

Subject Category: JSS2 Inter-University Research

PDF available here

• Responsible Representative: Nobuyuki Tsuboi, Professor, Department of Mechanical and Control Engineering, Kyushu Institute of Technology
• Contact Information: Nobuyuki Tsuboi(tsuboi@mech.kyutech.ac.jp)
• Members: Toshihiro Iwasa, Takahide Araki, Nobuyuki Tsuboi, Yoshiki Nishikawa, Tomoki Uzaki, Ryuji Takahashi, Ayu Agou, Kouhei Ozawa, Nicolas H. Jourdaine, Shota Goto, Kodai Shimomura, Kenta Murayama, Takuro Yoshino, Tomohiro Watanabe

Abstract

Fundamental studies on nozzles and combustors for Japanese rocket engines and supersonic engines are performed by using numerical simulations.

Reference URL

Please refer to ‘反応流体力学研究室/研究テーマ‘.

Reasons for using JSS2

Academic and applicative researches on fluid dynamics and combustion mechanism, and development of effective numerical methods are carried out in order to develop Japanese rocket engines and supersonic engines.

Achievements of the Year

Three-dimensional numerical simulations on a slit-shaped hydrogen jet under high momentum flux ratio in supersonic freestream are performed to evaluate the jet mixing. The results show that the jet penetration is high and hydrogen is transported in a span-wise direction and is distributed widely, as shown in Fig. 1. Multiple longitudinal vortices around the jet entrain the hydrogen jet and mix with the freestream, as shown in Fig. 2. In this mixing process, key parameters are jet trajectory and the strength of the vortex. These parameters strongly depend on the momentum flux ratio and pressure ratio.

Fig.1: Time-averaged hydrogen mass fraction contours.

Fig.2: Q value(50) isosurface contours. Color means velocity magnitude.

Publications

– Oral Presentations

[1] Toshihiro Iwasa, Keiichiro Fujimoto, Daiki Muto, Nobuyuki Tsuboi, Numerical Simulations of Hydrogen Jet Mixing in Supersonic Crossflow for Liquid Rocket Commanded Destruction, 12th Asian Computational Fluid Dynamics Conference, 0104, Yilan, Taiwan, October, 2018.

[2] Yoshiki Nishikawa, Nobuyuki Tsuboi, Takashi Ito, Satoshi Nonaka, Numerical Study on Aerodynamic Characteristics of Reusable Vehicle-eXperiment Rocket with Body-flap during Gliding, 15th International Conference on Flow Dynamics, GS1-30, Sendai, Japan, November, 2018.

Usage of JSS2

Computational Information

• Process Parallelization Methods: MPI
• Thread Parallelization Methods: OpenMP
• Number of Processes: 8 – 12
• Elapsed Time per Case: 141 Hour(s)

Resources Used

Fraction of Usage in Total Resources*1(%): 0.12

Details

Please refer to System Configuration of JSS2 for the system configuration and major specifications of JSS2.

*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.

JAXA Supercomputer System Annual Report April 2018-March 2019