JAXA Special Publication JAXA-SP-19-003E

Post-K Priority Issue 8D: Research and development of core technology
to innovate aircraft design and operation
Report Number: R18ECMP06
Subject Category: Competitive Funding
URL: https://www.jss.jaxa.jp/en/ar/e2018/9112/
Responsible Representative
Yuko Inatomi, Institute of Space and Astronautical Science, Department of Interdisciplinary Space Science
Contact Information
Ryoji Takaki (ryo@isas.jaxa.jp)
Members
Ryoji Takaki, Taku Nonomura, Seiji Tsutsumi, Yuma Fukushima, Soshi Kawai, Ikuo Miyoshi, Satoshi Sekimoto,Hiroshi Koizumi, Tomohide Inari, Ryota Hirashima, Yoshiharu Tamaki, Takuya Karatsu
Abstract
We develop a high-speed/high-precision computational program using a quasi-first principle method, which canfaithfully reproduce the actual flight environment to understand the true nature of fluid phenomena. Specifically,
we develop a high-precision compressible flow solver with geometric wall models and LES (Large EddySimulation) wall models based on hierarchical, orthogonal and equally spaced structured grids.
Ref. URL: http://www.postk-pi8.iis.u-tokyo.ac.jp/sub_d.html
Reasons for using JSS2
We need large computer like JSS2 because our calculations must be large scale computations. Moreover, JSS2
has a similar architecture to the our target computer called Post-K.
Achievements of the Year
We proceeded with the development of a compressible fluid analysis program FFVHC - ACE using a hierarchical,orthogonal and equally spaced structured grid method. In this fiscal year, a trial calculation for the aircraft of theactual detailed shape (JSM_CRM_LEG model) was performed using the immersed boundary method. Figure 1 isthe computational grid for the JSM_CRM_LEG model. Figure 2 shows the object surface of the landing gear
expressed in the flow solver. The reproducibility of the object surface is improved as the grid resolution improves.
Figure 3 shows the vorticity around the JSM_CRM_LEG model, where Mach number is 0.2, the Reynolds number
is 10 6, and attack angle is 7 degrees. The total number of grid points is about 800 million, of which the numberof fluid points is about 600 million.

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JAXA Supercomputer System Annual Report (April 2018-March 2019)

Fig. 1: The hierarchical, orthogonal and equally spaced structured grid around theJSM_CRM_LEG model.

Fig. 2: Shape reproducibility of complicated geometry.

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JAXA Special Publication JAXA-SP-19-003E

Fig. 3: Flow around the JSM_CRM_LEG model.
(Video. Video is available on the web.)

Publications- Oral Presentations
R. Takaki, Toward the achievement of the aerodynamic characteristic evaluation for real configurations and real
flight environments of aircraft, 4rd Symposium on Post-K computer Priority Issue 8.
- OtherRyoji Takaki, How to make an aerospace vehicle with supercomputer !? - Roles of supercomputer inmanufacturing -, 13th symposium to know K-computer in Mito - From K-computer to Post-K computer.

Usage of JSS2

Computational Information
Process Parallelization Methods

MPI

Thread Parallelization Methods

OpenMP

Number of Processes

256 - 600

Elapsed Time per Case

120 Hour (s)Resources Used
Fraction of Usage in Total Resources*1 (%): 3.88

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JAXA Supercomputer System Annual Report (April 2018-March 2019)

Details
Computational Resources
System Name

Amount of Core Time(core x hours)

Fraction of Usage*2 (%)

SORA-MA

36,154,361.50

4.43

SORA-PP

6,470.46

0.05

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

2,181.51

2.26/data

33,258.50

0.59/ltmp

12,472.17

1.07

Archiver Resources
Archiver Name

Storage Used (TiB)

J-SPACE

Fraction of Usage*2 (%)
36.60

1.28

*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.

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