JAXA Supercomputer System Annual Report February 2025-January 2026

Report Number: R25EDA201C22

Subject Category: Aeronautical Technology

PDF (to be added)

• Responsible Representative: Kanako Yasue, Aviation Technology Directorate, team leader, Aircraft Life-cycle Innovation Hub, Airmobility Digital Design Team
• Contact Information: Keita Kimura(kimura.keita@jaxa.jp)
• Members: Keita Kimura, Yasutada Tanabe

Abstract

To advance optimal design technologies for rotor blades used in rotorcraft, such as helicopters, this study investigates an aerodynamic optimization approach that combines high-fidelity CFD/CSD coupled analysis with optimization algorithms. To ensure wide-range applicability, multi-objective optimization is performed by considering both hover efficiency and cruise-flight efficiency.

The objective is to identify rotor blade configurations with reduced power consumption, while also determining the design variables that have the most significant impact on performance. By clarifying these key contributing factors, this approach aims to establish a design methodology that enables the development of high-performance rotor blades while reducing design effort.

Reference URL

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Reasons and benefits of using JAXA Supercomputer System

In CFD-based optimization, a large number of cases with several design variables need to be performed in the CFD analysis, and the use of a supercomputer is essential.

Achievements of the Year

Figure 1 shows an example of CFD analysis, presenting a visualization of tip vortices. In optimization-oriented simulations, it is important to minimize the computational cost as much as possible; however, it can be confirmed that sufficient grid resolution is maintained to preserve the tip vortex structures in the wake region.

Figure 2 presents a performance map with respect to the two objective functions used in the optimization algorithm. The horizontal axis represents the power consumption in hover, while the vertical axis represents the power consumption in cruise flight. Lower values in both axes indicate more promising design solutions.The optimization yields a design that improves both hover and forward-flight efficiency relative to the baseline.

Figure 3 illustrates an example of the blade elastic deformation history obtained from coupled CFD/CSD analysis. Changes in design variables, such as chord length and sweep angle, alter the structural properties of the blade (e.g., elastic axis location and stiffness). Therefore, it is important to appropriately account for these effects in performance evaluation. By conducting high-fidelity CFD/CSD analysis, optimization can be carried out while incorporating these structural and aeroelastic effects.

Fig.1: Example of CFD Analysis (Visualization of Tip Vortices)

Fig.2: Performance Map for Each Sample (Hover Power vs. Cruise Power)

Fig.3: Blade Elastic Deformation History (Cruise Condition, Azimuth vs. Deformation: Flap/Lead-Lag/Torsion)

Publications

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Usage of JSS

Computational Information

• Process Parallelization Methods: N/A
• Thread Parallelization Methods: OpenMP
• Number of Processes: 1
• Elapsed Time per Case: 100 Hour(s)

JSS3 Resources Used

Fraction of Usage in Total Resources*1(%): 0.41

Details

Please refer to System Configuration of JSS3 for the system configuration and major specifications of JSS3.

*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

*2: Fraction of Usage：Percentage of usage relative to each resource used in one year.

JAXA Supercomputer System Annual Report February 2025-January 2026