Study on a Propellant-Supply Electric Pump for Application to Deep Space OTV

JAXA Supercomputer System Annual Report February 2025-January 2026

Report Number: R25EDU10309

Subject Category: Space and Astronautical Science

Responsible Representative: Satoshi Nonaka, Institute of Space and Astronautical Science, Department of Space Flight Systems
Contact Information: Yusuke Maru(maru.yusuke@jaxa.jp)
Members: Yusuke Maru, Ami Mizumura, Ryota Miyajima, Kiwame Sakai, Keisuke Takahashi, Hibiki Yamaguchi

Abstract

The objective of this study is to define concrete performance targets for an electrically driven pump system that can contribute to higher overall performance of the DSOTV system. This will be achieved through a conceptual study of the electric pump system based on DSOTV system analyses, along with an evaluation of the key technological elements identified in that process. On the JSS, flow analyses of the pump will be conducted to improve its fluid performance.

Reference URL

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Reasons and benefits of using JAXA Supercomputer System

To analyze the flow field of a pump, which is a rotating machine, unsteady simulations are essential--even when its periodicity can be exploited. As a result, the computations become relatively large-scale. By utilizing the resources of the JSS, we are able to perform analyses of this magnitude.

Achievements of the Year

A pump increases fluid pressure, so the overall system efficiency fundamentally depends on its pressure-rise efficiency.This study aims to clarify how blade and passage geometries in a cascade pump affect performance, and to identify mechanisms that can guide performance improvements. Using an existing cascade pump as a baseline, we evaluated the impact of geometric modifications through CFD analyses, focusing in particular on the blade-casing clearance.

Lowering pump inlet pressure reduces tank pressure requirements, enabling tank weight reduction. However, excessive pressure reduction risks cavitation. The cavitation characteristics of cascade pumps have not been well documented, so we investigated the onset and effects of cavitation through CFD analysis and experiments.

Fig.1: Comparison of the flow fields for different blade-casing clearance settings

Fig.2: Comparison between experimental flow visualization and CFD results

Publications

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Usage of JSS

Computational Information

Process Parallelization Methods: MPI
Thread Parallelization Methods: OpenMP
Number of Processes: 256
Elapsed Time per Case: 8.3 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.

Computational Resources
System Name	CPU Resources Used (Core x Hours)	Fraction of Usage*2(%)
TOKI-SORA	0.00	0.00
TOKI-ST	67580.56	0.07
TOKI-GP	0.00	0.00
TOKI-XM	0.00	0.00
TOKI-LM	0.00	0.00
TOKI-TST	4536.04	0.07
TOKI-TGP	0.00	0.00
TOKI-TLM	0.00	0.00

File System Resources
File System Name	Storage Assigned (GiB)	Fraction of Usage*2(%)
/home	0.00	0.00
/data and /data2	102400.00	0.67
/ssd	0.00	0.00

Archiver Resources
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 Resources
	ISV Software Licenses Used (Hours)	Fraction of Usage*2(%)
ISV Software Licenses (Total)	165.32	0.12

*2: Fraction of Usage：Percentage of usage relative to each resource used in one year.