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
- 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.

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).
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.
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 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 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