Fundamental Study on Jet Vectoring using Coanda Effect

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K03936
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 19010:Fluid engineering-related
• Research Institution: Kogakuin University
• Principal Investigator: SATO KOTARO 工学院大学, 工学部, 教授 (80252625)
• Co-Investigator(Kenkyū-buntansha): 横田 和彦 青山学院大学, 理工学部, 教授 (70260635)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: Jet / Frequency / Coanda effect / Vectoring

Outline of Final Research Achievements

In this study, the influence of synthetic jets near a circular cylinder on the flow characteristics of a primary jet was investigated. The main results obtained in the study were that the direction of the primary jet flow can be controlled using the secondary synthetic jet, and the degree of jet deflection depends on the frequency of the velocity oscillation for the secondary synthetic jet under an identical momentum ratio. Furthermore, when using the synthetic jet as the secondary flow, a controllable region larger than that obtained when using a steady and continuous injection or suction flow is expected. This is because secondary flow is generated using the ratio of the momentum between the primary jet and the secondary flow at the slot exit in conjunction with the dimensionless frequency of the synthetic jet based on the velocity of the primary flow at the slot exit.

Free Research Field

流体工学

Academic Significance and Societal Importance of the Research Achievements

噴流に関する研究は失速抑制や抵抗軽減，流体機械での不安定流れの抑制，空調・エアカーテンの高性能化などを目的として盛んに行われきた．最近ではウイルス飛沫感染防止を目的として換気・空調の気流制御に噴流技術を利用する研究が始まっている．噴流の進行方向を自由に調整することが可能になれば，より一層広い分野で噴流技術が役立つことは間違いない．本研究では幾何形状の変化を伴わない噴流の方向制御を目指し，その実現のためにシンセティックジェットが適用された．シンセティックジェットの無次元周波数による流れ場の制御と噴流偏向メカニズムについて議論がなされ，シンセティックジェットによる流動制御の可能性が示された．