Numerical Study on Combustible Flow in Supersonic Flight Engines and Rocket Engines
JAXA Supercomputer System Annual Report February 2025-January 2026
Report Number: R25EACA01
Subject Category: JSS Inter-University Research
- Responsible Representative: Nobuyuki Tsuboi, Professor, Kyuchu Institute of Technology
- Contact Information: Nobuyuki Tsuboi(tsuboi@mech.kyutech.ac.jp)
- Members: Takumi Ito, Tsuyoshi Ifuku, Nobuyuki Tsuboi, Yuta Toshima
Abstract
Numerical analysis of the aerodynamic characteristics of the RV-X will contribute to improved aircraft design and accurate guidance to the landing site.
Reference URL
N/A
Reasons and benefits of using JAXA Supercomputer System
We need to use a supercomputer for numerical analysis, and JSS3 has high performance and is easy to use as a university cooperative use.
Achievements of the Year
We conducted an aerodynamic analysis of the RV‑X during turning flight using both steady and unsteady computational approaches to investigate how time accuracy affects the results. (Fig.1) presents the obtained drag coefficient histories. Even under conditions with relatively small separation scales—up to an angle of attack of 30[deg]—noticeable differences in the predictions were observed. (Fig.2) and (Fig.3) show the Mach number distributions at an angle of attack of 60. At 60[deg], the unsteady simulation revealed periodic vortical structures that were not captured by the steady calculation, indicating that the steady approach fails to represent the time‑dependent movement of the separation region. By contrast, results at an angle of attack of 180[deg] were in good agreement between the two methods. Because differences between steady and unsteady calculations were confirmed for conditions other than near 180[deg], the turning‑flight analysis of the RV-X should, except in the vicinity of 180[deg] angle of attack, preferably be performed using unsteady calculations.
Fig.1: Drag cofficient
Fig.2: Mach number distribution at an angle of attack of 60[deg] (steady calculation)
Fig.3: Mach number distribution at an angle of attack of 60[deg] (unsteady calculation)
Publications
N/A
Usage of JSS
Computational Information
- Process Parallelization Methods: MPI
- Thread Parallelization Methods: OpenMP
- Number of Processes: 9
- Elapsed Time per Case: 20 Hour(s)
JSS3 Resources Used
Fraction of Usage in Total Resources*1(%): 0.08
Details
Please refer to System Configuration of JSS3 for the system configuration and major specifications of JSS3.
| System Name | CPU Resources Used(Core x Hours) | Fraction of Usage*2(%) |
|---|---|---|
| TOKI-SORA | 101914.81 | 0.00 |
| TOKI-ST | 657926.38 | 0.68 |
| TOKI-GP | 0.00 | 0.00 |
| TOKI-XM | 0.00 | 0.00 |
| TOKI-LM | 0.00 | 0.00 |
| TOKI-TST | 0.00 | 0.00 |
| TOKI-TGP | 0.00 | 0.00 |
| TOKI-TLM | 0.00 | 0.00 |
| File System Name | Storage Assigned(GiB) | Fraction of Usage*2(%) |
|---|---|---|
| /home | 0.00 | 0.00 |
| /data and /data2 | 0.00 | 0.00 |
| /ssd | 0.00 | 0.00 |
| 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 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 2025-January 2026