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Physics and Modeling in Hypersonic and Transonic Flow toward Establishing Reentry Technology

JAXA Supercomputer System Annual Report February 2023-January 2024

Report Number: R23EACA53

Subject Category: JSS Inter-University Research

PDF available here

  • Responsible Representative: Naofumi Ohnishi, Professor, Tohoku University
  • Contact Information: Yasuhito Okano, Tohoku University(yasuhito.okano.p4@dc.tohoku.ac.jp)
  • Members: Naofumi Ohnishi, Yasuhito Okano, Hiroki Sakamoto

Abstract

Critical issues for designing a reentry capsule are mainly the prediction of aerodynamic heating in hypersonic flows and dynamic instability in transonic flows. In hypersonic flows, the heating rate can be increased due to the transition from the laminar to turbulence at boundary layer. In transonic flows, the dynamic instability can be caused by the flow near the capsule side or capsule base. Both are computationally expensive because of the high Reynolds number and chemical reaction for prediction of the aerodynamic heating and longer time scale of the capsule motion than that of the fluid for prediction of dynamic instability. Although modeling is needed to overwhelm this problem, mechanisms of the physical phenomena are unknown in detail. In this study, numerical simulations are performed using the supercomputer to clarify the mechanism and conduct modeling. This year, we mainly used the supercomputer to perform numerical simulations of the dynamic instability at transonic flows.

Reference URL

N/A

Reasons and benefits of using JAXA Supercomputer System

Numerical simulations of the Navier-Stokes equation which is coupled with the pitch-direction equation of motion are conducted. Accurate numerical simulations are required to capture the turbulence behavior. In addition, the time scale of the reentry capsule motion is much longer than that of the fluid. Thus, the use of the supercomputer is necessary.

Achievements of the Year

This year, the dynamic instability of HRV-type capsules is investigated at Mach 1.2. The self-excited oscillation is observed at this flow condition in an experiment. The increase in the oscillation amplitude is confirmed even in our numerical simulation (Fig. 1). Thus, the same trend in the experiment is reproduced successfully. According to the analysis of the numerical simulation result, we found that the dynamic instability of the HRV-type capsule is caused by the hysteresis of the boundary layer separation on the capsule shoulder. Moreover, DMD analysis revealed that the recirculation region on the capsule wake has a non-small influence on the dynamic instability. In future work, advanced analysis and numerical analysis of subsonic flow will be conducted.

Annual Reoprt Figures for 2023

Fig.1: Time-series pitch angle deviation and pitching moment coefficients

 

Publications

– Peer-reviewed papers

(1) Yasuhito Okano, Shintaro Sato, and Naofumi Ohnishi, Numerical study toward verification of analogy between hypersonic turbulent transition and directed percolation, Journal of Evolving Space Activities, Vol. 1, No. 56, 2023.

(2) Hiroki Sakamoto, Shintaro Sato, and Naofumi Ohnishi, Hypersonic boundary layer development on tube wall in long-distance propagation of shock wave, Journal of Evolving Space Activities, Vol. 1, No. 73, 2023.

– Oral Presentations

(1) Yasuhito Okano, Shintaro Sato, Naofumi Ohnishi, and Hiroki Nagai, Numerical Analysis of Free Oscillation of Reentry Capsule on Suppression of Dynamic Instability in Transonic Flow, 34th ISTS and 12th NSAT, 6, June, 2023.

(2) Hiroki Sakamoto, Shintaro Sato, and Naofumi Ohnishi, Hypersonic Boundary Layer Instability in Long-Distance Propagation of Shock Wave, The 34th International Symposium on Shock Waves, 16, July, 2023.

(3) Hiroki Sakamoto, Shintaro Sato, and Naofumi Ohnishi, Flow Instability in a Hypersonic Boundary Layer Behind a Propagating Shock Wave, 76th Annual Meeting of the Division of Fluid Dynamics, 19, November, 2023.

Usage of JSS

Computational Information

  • Process Parallelization Methods: MPI
  • Thread Parallelization Methods: N/A
  • Number of Processes: 360 – 720
  • Elapsed Time per Case: 360 Hour(s)

JSS3 Resources Used

 

Fraction of Usage in Total Resources*1(%): 0.55

 

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 4165.39 0.00
TOKI-ST 4359202.80 4.71
TOKI-GP 0.00 0.00
TOKI-XM 0.00 0.00
TOKI-LM 3362.20 0.26
TOKI-TST 1463.45 0.02
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 133020.00 0.82
/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)
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 2023-January 2024