JAXA Supercomputer System Annual Report April 2020-March 2021

Report Number: R20EG3214

Subject Category: Research and Development

PDF available here

• Responsible Representative: Taro Shimizu, Research and Development Directorate, Research Unit III
• Contact Information: Satoshi Ukai(ukai.satoshi@jaxa.jp)
• Members: Hideyo Negishi, Yoichi Ohnishi, Miki Nishimoto, Yu Daimon, Ashvin Hosangadi, Osamu Fukasawa, Shinji Ohno, Andrea Zambon, Takenori Nakajima, Takashi Amemiya, Hironori Fujiwara, Hiroumi Tani, Keiichiro Fujimoto, Tetsufumi Ohmaru, Taroh Fukuda, Masashi Toyama, Daiki Muto, Satoshi Ukai, Yuuichi Kunishima

Abstract

Turbopumps are still one of key components in liquid rocket engine development in terms of cost, time, and risks. Furthermore, a turbopump itself is a complex system consisting of sub-components such as pump, turbine, bearing, balance piston, sealing and so on. From numerical simulation technology point of view, there is no technology able to evaluate performance of an entire turbopump system in the world. And also, accuracy and fidelity of numerical simulation technology for sub-components are still poor and cannot be used to reduce the number of experiments. Therefore, experiments are indispensable to evalute feasibility of considered design in engine development.

In this study, numerical simulation technology of an entire turbopump system able to be applicable in engine design phase has been developed enhancing accuracy and fedelity. We are aiming at reducing cost and time for future engine development by making full use of our numerical simulation to reduce the number of experiments. And also, innovative design methodology for higher performance rocket turbopumps has been investigated by using our numerical simulations.

Reference URL

Please refer to https://stage.tksc.jaxa.jp/jedi/simul/index.html .

Reasons and benefits of using JAXA Supercomputer System

In this study, JSS2 has been used because of the following reasons:

(1) To make it possible to perform large-scale numerical simulations with high accuracy and fidelity

(2) To produce a lot of computed results on time within limited short period of time under JAXA's rocket development

(3) To ensure information security about rocket-related technical information in JAXA's network only

Achievements of the Year

In the fiscal year 2019, the three-dimensional compressible URANS simulation taking into account to simulate flow within turbines . The computed results showed that turbine efficiencies agreed well with experimental results within 4% error. Also, a new method to predict a variable stress on turbinblades under resonace conditions is proposed and tested, and numerical predictions were shown to be in the same order of the experimental results.

The developed numerical simulation approach has been employed in the booster engine LE-9 development of H3 launch vehicle.

Fig. 1 shows the flow within the turbines, and Fig 2. discribes the unsteady pressure interference with turbine blades.

Fig.1(video): Pressure profile within a turbine

Fig.2(video): Unsteady Pressure interference with turbine blades

Publications

N/A

Usage of JSS

Computational Information

• Process Parallelization Methods: MPI
• Thread Parallelization Methods: FLAT
• Number of Processes: 128 - 16000
• Elapsed Time per Case: 300 Hour(s)

Resources Used(JSS2)

Fraction of Usage in Total Resources*1(%): 1.06

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.

Resources Used(JSS3)

Fraction of Usage in Total Resources*1(%): 0.79

Details

Please refer to System Configuration of JSS3 for the system configuration and major specifications of JSS3.

*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 2020-March 2021