Research on three-dimensional cavity flow

JAXA Supercomputer System Annual Report February 2021-January 2022

Report Number: R21ECWU12

Subject Category: Cooperative Graduate School System

Responsible Representative: Yuya ohmichi, Aeronautical Technology Directorate,Numerical Simulation Research Unit
Contact Information: Yuya ohmichi (ohmichi.yuya@jaxa.jp)
Members: Miumi Maezawa, Yuya Ohmichi

Abstract

It is well known that rectangular-shaped cavities, such as those found in aircraft landing gear storage areas, can cause noise due to self-excited oscillation caused by an unsteady fluid phenomenon. In this study, the phenomenon of self-excited oscillation inside cavities was investigated by numerical fluid simulations

Reference URL

N/A

Reasons and benefits of using JAXA Supercomputer System

Numerical simulation of unsteady flow fields is computationally expensive

Achievements of the Year

The spatio-temporal structure of the cavity flow with a Mach number of 1.4 is visualized as shown in Figures 1 and 2 using dynamic mode decomposition. The visualization results show that the sidewalls change the spanwise velocity structure. It is also suggested that the sidewalls affect the pressure fluctuations that cause aerodynamic noise.

Fig.1: Spatial structure of spanwise velocity without sidewalls (St=0.1)

Fig.2: Spatial structure of spanwise velocity with sidewalls (St=0.1)

Publications

N/A

Usage of JSS

Computational Information

Process Parallelization Methods: MPI
Thread Parallelization Methods: OpenMP
Number of Processes: 256
Elapsed Time per Case: 50 Hour(s)

JSS3 Resources Used

Fraction of Usage in Total Resources*1(%): 0.11

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	2091789.19	0.10
TOKI-ST	85995.40	0.11
TOKI-GP	0.00	0.00
TOKI-XM	0.00	0.00
TOKI-LM	13463.57	1.00
TOKI-TST	0.00	0.00
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	600.00	0.60
/data and /data2	102048.00	1.09
/ssd	5140.00	1.33

Archiver Resources
Archiver Name	Storage Used (TiB)	Fraction of Usage*2(%)
J-SPACE	6.32	0.04

*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)	2028.79	1.42

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