Statistics and dynamics of precession-driven turbulence of non-Newtonian fluids

2014 Fiscal Year Final Research Report

• Project/Area Number: 24360071
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Fluid engineering
• Research Institution: Osaka University
• Principal Investigator: GOTO Susumu 大阪大学, 基礎工学研究科, 准教授 (40321616)
• Co-Investigator(Kenkyū-buntansha): KAWAHARA Genta 大阪大学, 大学院基礎工学研究科, 教授 (50214672) ; SHIMIZU Masaki 大阪大学, 大学院基礎工学研究科, 助教 (20550304)
• Co-Investigator(Renkei-kenkyūsha): NAKAHARA Akio 日本大学, 理工学部, 准教授 (60297778)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 乱流 / 歳差運動 / 非ニュートン流体 / 界面活性剤 / 粒子画像流速測定 / レーザードップラー流速測定 / 直接数値シミュレーション / 回転流体

Outline of Final Research Achievements

We have constructed a new experimental platform for turbulence research by using the precession of a container. This system has good flow reproducibility as well as the advantage that numerical simulations can be easily conducted under the exactly same conditions as in the laboratory. We performed laboratory experiments (PIV/LDV) and direct numerical simulations to reveal the detailed statistics and dynamics of turbulence of a Newtonian fluid confined in spherical and spheroidal cavities. Then, we investigated the modulation of these turbulence due to the addition of a small amount of surfactant (CTAC). Under our experimental conditions, the turbulence modulation occurs only in a central region of the container, and coherent vortices near the container wall are hardly affected by the surfactant additives. These observations are shown to be consistent with the rheological properties of the surfactant solution.

Free Research Field

流体工学