权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Development of Boundary Layer Control by Enhancing Peculiar Pulsation in Two-Phase Turbulent Flow

增强两相湍流中奇异脉动的边界层控制研究进展

基本信息

批准号：
20J20435
负责人：
田中泰爾
金额：
$ 2.18万
依托单位：
Hokkaido University
依托单位国家：
日本
项目类别：
Grant-in-Aid for JSPS Fellows
财政年份：
2020
资助国家：
日本
起止时间：
2020-04-24 至 2023-03-31
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-20J20435/
关键词：
摩擦抵抗低減乱流境界層気液二相流ボイド波

项目摘要

本年度は，乱流境界層への周期的に空気流量を変動させた気泡注入（間欠的気泡注入）による抵抗低減技術の開発を目的として，①船長36mの平定模型船を用いた抵抗低減効果の調査，②同平定模型船に生じた気液二相流乱流境界層についての現象解明，③水平チャネル乱流における気液二相流から単相流への移行時の乱流変調現象の解明の3つの研究を実施した．研究①の平底模型船を用いた実験では，準実船規模環境においてボイド波を活用することによる摩擦抵抗低減促進効果を調査した．模型船にかかる全抗力を計測結果し，特定の周波数で注入空気流量を周期変動させることにより抵抗低減率が最大になることを示した．模型船底面における局所壁面せん断応力の長手方向分布を計測し，長い流下距離に適用可能な抵抗低減効果の下流遷移モデルを提案した．モデルを用いた実船大での抵抗低減率の推定を行い，ボイド波の活用により実際の船において抵抗低減率が向上する予測を与えた．研究②では，船底を流れる気液二相流の流動状態と局所せん断応力の時系列データ同期解析を行った．ボイド率の周期変動に対応して壁面せん断応力が周期変動し，この応答が長手方向に伝播する過程を明らかにした．研究③は，間欠的気泡注入により抵抗低減が促進される瞬間に焦点を当てた．乱流境界層中の速度分布を高空間解像度で取得するためにPTV（粒子追跡法）を行い，平均流速およびレイノルズ応力を取得した．この結果は，気泡の通過により乱流せん断が一時的に約80%抑制されることを示した．以上の内容を含め，国際学会誌Ocean Engineeringでの発表2件（筆頭著者），日本トライボロジー学会学会誌「トライボロジスト」での発表1件（共著），国際学会発表2件（本人口頭発表1件，ポスター発表1件），国内学会発表4件（本人口頭発表3件，共著1件）を行った．

This year, the air flow in the turbulent flow cycle (insufficient bubble injection) in order to resist the low-level technology start-up purpose, 1 ship length 36 m leveling model ship using the engine to resist low performance, 2 the same as the leveling model ship, the two-phase flow boundary is the same as that of the model ship. (3) horizontal turbulent flow and liquid two-phase flow. During the migration of liquid two-phase flow, the simulation of turbulent flow is studied in this paper. the purpose of this paper is to study the use of a flat-bottomed model ship, and to prepare for the environmental protection of the ship. The model ship is equipped with low-temperature friction resistance to improve the performance of the ship. The results of the model ship total resistance test A specific cycle wave number is injected into the air flow cycle, and the maximum failure rate is shown to be resistant to low running. the distribution of breaking force on the wall of the underside of the model ship is calculated in the long hand direction, and the long flow distance is used as a possible countermeasure against low fruit downflow. The proposal is proposed to resist the downflow of the ship. The ship uses the ship ship to resist the low load rate and the low load rate is presumed. During the study, the two-phase flow in the bottom of the ship, the breaking force of the liquid two-phase flow in the bottom of the ship, the breaking force of the liquid two-phase flow, the breaking force of the liquid two-phase flow, the breaking force of the liquid two-phase flow, the breaking force of the two-phase flow in the bottom of the ship, the breaking force of the liquid two-phase flow, the breaking force of the liquid two-phase flow in the bottom of the ship, the breaking force of the liquid two-phase flow, the breaking force of the liquid two-phase flow in the bottom of the ship, the breaking force of the liquid two-phase flow, the breaking force of the liquid two-phase flow in the bottom of the ship, the breaking force of the liquid two-phase flow, the breaking force of the liquid two-phase flow in the bottom of the ship, the breaking force of the liquid two-phase flow, the breaking force of the liquid two-phase flow, the breaking force of the liquid two-phase flow, the In response to a long-hand broadcast, the process is clear. After 3 years of study, low temperature bubbles are injected into the air to resist the low temperature and promote the focus of the shock. The velocity distribution in the turbulent boundary, the high altitude resolution, and the particle pursuit PTV (particle pursuit method) performance, and the average velocity velocity measurement, the average flow rate, the temperature, the temperature, the temperature The contents of the above information are implied. There are 2 tables of the International Society of International Studies (Ocean Engineering) (authors), 1 table of the Japanese Society of Health and Health Association (co-author), and 2 tables of the International Society of International Studies (I have a copy of the list 1, and I have a table 1 of it). There are 4 tables in the domestic Society (3 in my mouth, 1 in total).