本文へ移動

サイトナビゲーションへ移動

検索ボックスへ移動

サイドバーへ移動

ここは、本文エリアの先頭です。

Construction of LES model for high Mach number multiphase flow based on DNS analysis

JAXA Supercomputer System Annual Report April 2019-March 2020

Report Number: R19EACA11

Subject Category: JSS2 Inter-University Research

PDF available here

  • Responsible Representative: Kota Fukuda, Ascossiate Professor, Tokai University
  • Contact Information: Kota Fukuda, Ascossiate Professor, Tokai University(fukuda@tokai-u.jp)
  • Members: Kota Fukuda, Taku Nonomura

Abstract

In order to construct LES model for high Mach number multi-phase turbulent flow, direct numerical simulation (DNS) of high Mach number and low Reynolds number flow around a particle will be carried out and construction of its data base and examination of the flow phenomena will be conducted.

Reference URL

N/A

Reasons and benefits of using JAXA Supercomputer System

In this project, direct numerical simulation (DNS) of high Mach number and low Reynolds number flow around a particle and construction of the data base will be carried out using a boundary-fitted coordinate system. Large scale numerical simulation is essential to construct the data base.

Achievements of the Year

In this study, the transonic flow over an isolated sphere up to a Reynolds number of 1,000 was investigated by the direct numerical simulation (DNS) of the three-dimensional compressible Navire-Stokes equations. The Mach number effects on the types of flow patterns, the flow geometry, and the drag coefficient were investigated. As a result, we confirmed that (1) the wake is significantly stabilized at the transonic regime; (2) the increment of the drag coefficient in the continuum regime due to the Mach number effect can be characterized with regardless of the Reynolds number even though low-Reynolds number conditions, (3) and the increment of the pressure and viscous drag coefficients are predictable by Prandtl-Glauert transform and the movement of the position of the separation point, respectively, up to a Mach number of approximately 0.8.

Annual Reoprt Figures for 2019

Fig.1: Mach number and Reynolds number effects on the wake sructure of a stationaly isolated sphere (distribution of the absolute value of the density).

 

Annual Reoprt Figures for 2019

Fig.2: Relationship between the separation point and the total drag coefficient

 

Annual Reoprt Figures for 2019

Fig.3: The map of flow regime of stationaly sphere at the compressible low-Reynolds number flow.

 

Publications

– Oral Presentations

Nagata, T., Nonomura, T., Takahashi, S., and Fukuda, K., “onsideration of Mach and Reynolds numbers effect on flow field and drag coefficient of a particle in transonic flow at Reynolds number between 300 and 1000,” Proceedings of the 51st Fluid Dynamics Conference / the 37th Aerospace Numerical Simulation Symposium, 1E08, Tokyo, July (2019)

Usage of JSS2

Computational Information

  • Process Parallelization Methods: MPI
  • Thread Parallelization Methods: OpenMP
  • Number of Processes: 16 – 289
  • Elapsed Time per Case: 200 Hour(s)

Resources Used

 

Fraction of Usage in Total Resources*1(%): 0.29

 

Details

Please refer to System Configuration of JSS2 for the system configuration and major specifications of JSS2.

Computational Resources
System Name Amount of Core Time
(core x hours)
Fraction of Usage*2(%)
SORA-MA 2,523,635.64 0.31
SORA-PP 0.00 0.00
SORA-LM 0.00 0.00
SORA-TPP 0.00 0.00

 

File System Resources
File System Name Storage Assigned
(GiB)
Fraction of Usage*2(%)
/home 42.35 0.04
/data 24,530.76 0.42
/ltmp 3,044.58 0.26

 

Archiver Resources
Archiver Name Storage Used
(TiB)
Fraction of Usage*2(%)
J-SPACE 18.89 0.48

*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 2019-March 2020