Thermal-Fluid Analysis of Rocket Propulsion Systems
JAXA Supercomputer System Annual Report February 2025-January 2026
Report Number: R25ERSC85
Subject Category: Space Technology
- Responsible Representative: Kazuki Sakaki,R&D Dept, Interstellar Technologies Inc.
- Contact Information: Yoshifumi Sakata(yoshifumi.sakata@istellartech.com)
- Members: Yoshifumi Sakata, Ryunosuke Uchiyama, Yutaro Furiichi
Abstract
Accurate prediction of thermal fluid phenomena inside propellant tanks during rocket flight is crucial for the efficient utilization of propellants.
This project utilizes CFD (Computational Fluid Dynamics) to replicate the thermal behavior involving phase change within the tank, where multiple complex factors intertwine, such as flight acceleration, pressurant gas injection from the top, propellant discharge from the bottom, and radiant heat from the tank wall.
The objective is to quantitatively obtain the internal pressure and temperature history, as well as the required pressurant gas flow rate, and to apply these findings to the development of rocket propulsion systems.
Reference URL
N/A
Reasons and benefits of using JAXA Supercomputer System
High-fidelity multiphase flow analysis involving propellant phase changes requires massive parallel computing power and large memory capacity to process extensive mesh data.
Achievements of the Year
Using the JSS, the thermal behavior of propellant in a rocket tank during flight was analyzed. In this study, a 2D axisymmetric model simulating a full-scale propellant tank was developed, and unsteady simulations were performed using ANSYS Fluent 2022 R2. The VOF method, accounting for phase change, was employed for the analysis. To replicate in-flight conditions, the simulation incorporated pressurized gas injection from the tank top, liquid propellant discharge from the bottom, and flight acceleration. Additionally, radiant heat transfer to the tank wall was included as a boundary condition. As a result, quantitative data were obtained for the liquid surface behavior, pressure and temperature history, evaporation/condensation rates, and the required pressurant gas flow rate.
Fig.1: Contours of gas volume fraction and temperature in the propellant tank
Publications
N/A
Usage of JSS
Computational Information
- Process Parallelization Methods: MPI
- Thread Parallelization Methods: OpenMP
- Number of Processes: 36
- Elapsed Time per Case: 4 Hour(s)
JSS3 Resources Used
Fraction of Usage in Total Resources*1(%): 0.01
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 | 0.00 | 0.00 |
| TOKI-ST | 1478.48 | 0.00 |
| TOKI-GP | 28702.94 | 0.46 |
| 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 | 46566.13 | 0.31 |
| /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