JAXA Supercomputer System Annual Report April 2018-March 2019

Report Number: R18EACA41

Subject Category: JSS2 Inter-University Research

PDF available here

• Responsible Representative: Makoto Sato, Associate Professor, Kogakuin University
• Contact Information: Makoto Sato, Kogakuin University(msato@cc.kogakuin.ac.jp)
• Members: Makoto Sato, Daichi Ogasawara, Yodai Suzuki

Abstract

Mars helicopter project is now going. Since the atmospheric density on Mars is about 1/100, the sound of speed is about 3/4 compared with those on Earth, we need to develop the high performance heli-rotor. In JAXA, the experimental measurements of the heli-rotor performance at low-Reynolds number condition have been conducted. In the present research, we conduct numerical simulations on the rotational flat-plate-airfoil flow in order to clarify the characteristics of the flow field.

Reference URL

N/A

Reasons for using JSS2

We need to conduct the large-scale simulations on the rotational wing flow using “rFlow3d”, which has been developed in JAXA.

Achievements of the Year

We have conducted the numerical simulation on the rotational flat-plate-airfoil flow. The computational object and conditions are decided based on the experiments at Tohoku University[1].

Figure 1 shows the schematic diagram of computational objects. The computational parameters are the Reynolds number(3,870-77,300), angle of attack(0-30) and aspect ratio(2-4). Here, the results of AR=4 cases are shown. The flow solver is rFLow3D, which has been developed at JAXA.

Figure 2 shows the coefficients of thrust and torque with experimental data. The simulation results are good agreement with those of experiment, except for the large angle of attack cases. Figure 3 shows vortex structures around flat-plate-airfoil. The leading-edge vortex and tip vortex can be observed. These vortices are interacted with each other. Figure 4 shows the coefficients of surface friction with experimental data. The simulation results are good agreement with that of experiment.

These results indicate that the present simulations are sufficiently reliable.

[1] Okoucuhi, M. “Experimental research on aero-characteristics of rotor at low-Reynolds number condition”, Master Thesis of Tohoku University, (2013).

Fig.1: Schematic diagram of computational object

Fig.2: Thrust and torque coefficients

Fig.3: Vortex structures around airfoil

Fig.4: Friction coefficients

Publications

– Oral Presentations

Daichi Ogasawara, Makoto Sato, Yasutada Tanabe, Hideaki Sugawara, “Numerical simulations on rotational flat-plate-airfoil flow using rFlow3D”, 1st Symposium on Mars helicopter, 2019.

Usage of JSS2

Computational Information

• Process Parallelization Methods: N/A
• Thread Parallelization Methods: OpenMP
• Number of Processes: 1
• Elapsed Time per Case: 400 Hour(s)

Resources Used

Fraction of Usage in Total Resources*1(%): 0.17

Details

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

*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 2018-March 2019