Proposal of methods to improve problems in direct numerical simulation of aerodynamic sound

Research Project

Project/Area Number	16K18021
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Multi-year Fund
Research Field	Fluid engineering
Research Institution	Japan Coast Guard Academy (Center for Research in International Marine Policy) (2018) Hiroshima National College of Maritime Technology (2017) Central Research Institute of Electric Power Industry (2016)
Principal Investigator	WAKAMATSU YUKI 海上保安大学校(国際海洋政策研究センター), 国際海洋政策研究センター, 講師 (30589304)
Project Period (FY)	2016-04-01 – 2019-03-31
Project Status	Completed (Fiscal Year 2018)
Budget Amount *help	¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000) Fiscal Year 2018: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000) Fiscal Year 2017: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000) Fiscal Year 2016: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Keywords	流体力学 / 数値計算 / 計算手法 / 空力音 / シミュレーション工学 / 流体工学
Outline of Final Research Achievements	The first result of this research is to clarify the problem of the concept of the order of accuracy of the combination of compact schemes in non-periodic boundary conditions. Specifically, conventionally, the order of accuracy of the compact scheme has not taken into consideration the influence of the difference scheme of the boundary, but according to this research, the order of accuracy of the combination of the compact schemes is influenced by the difference scheme used for the boundary was clarified using mathematical formulas. The second result of this research is that the high resolution explicit difference scheme under the calculation conditions used in this research are suitable for the computation of aerodynamic sound as well as the compact scheme.
Academic Significance and Societal Importance of the Research Achievements	本研究成果の学術的な意義は、非周期境界条件におけるコンパクトスキームの精度の次数の考え方の問題点を指摘したことにある。具体的には、本研究成果によって、コンパクトスキーム組み合わせの精度の次数は境界に用いる差分スキームの影響を受けることを数式を用いて明らかにした。本研究成果の社会的な意義は、コンパクトスキームの組み合わせの精度の次数の課題を新たに明らかにするとともに、コンパクトスキームと陽的スキームを用いた場合の空力音の計算結果に与える影響について本研究で用いた計算条件において定量的に示したことにある。