Analysis of Dynamics of the Cloud Cavitation and its Control

云空化动力学分析及其控制

• 批准号: 11450071
• 负责人: MATSUMOTO Yoichiro
• 金额: $ 9.22万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B).
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11450071/
• 关键词: Erosion; Cavitation; Hydrofoil; Numerical; Lift Coefficient; Drag Coefficient; Void Fraction; Pressure Distribution; Cavitation; Bubble Dynamics; Pressure Wave; Numerical Analysis; Cavitation Erosion; Bubbly Flow; External Flow; Numerical S

It is well known that a cloud cavitation is one of the most destructive forms of cavitation. In the present study, the set of equations for the motion of a spherical bubble cloud is formulated and the behavior of bubble clouds are simulated numerically under the situation of sudden change of surrounding pressure. To study the collapse of cloud cavitation more accurately, the internal phenomena of each bubble and the compressibility of liquid are considered in the governing equations. An inward propagating shock wave is formed during the collapse of bubble cloud and the shock wave is focused in the center region of the cloud. This makes a violent bubble collapse, which cause a high emitted pressure from the bubbles, which is several hundreds times larger than the single bubble collapse. Furthermore, a new numerical method for simulating cavitating flows around hydrofoil is developed. Cloud cavitation is modeled with perfectly spherical bubbles whose radii change with Rayleigh-Plesset equation. The bubbles are also allowed to have slip velocities so that the bubble accumulation could be simulated. Psedocompressibility concept for incompressible flow simulation is extended for the present systems of equations for efficient and robust computations. Computations of two-and three-dimensional cavitating flows verify the present method and show its capability to the practical applications.

众所周知，云状空化是最具破坏性的空化形式之一。本文建立了球形气泡云的运动方程组，并对周围压力突变情况下气泡云的行为进行了数值模拟。为了更精确地研究云状空化的溃灭过程，在控制方程中考虑了气泡内部现象和液体的可压缩性。在气泡云溃灭过程中，形成了一个向内传播的激波，激波聚焦在气泡云的中心区域。这使得剧烈的气泡破裂，这导致来自气泡的高发射压力，其比单个气泡破裂大几百倍。在此基础上，发展了一种新的数值方法来模拟绕水翼的空化流动。云空泡模型采用理想球形气泡，气泡半径随Rayleigh-Plesset方程变化。还允许气泡具有滑移速度，使得可以模拟气泡累积。本文将不可压流动模拟的拟压缩性概念推广到现有的方程组中，以提高计算效率和鲁棒性。通过对二维和三维空化流的计算，验证了本文方法的有效性和实用性。

项目成果

島田正仁,松本洋一郎,小林孝: "クラウドキャビテーションの崩壞挙動に及ぼす気泡核分布の影響"日本機械学会論文集(B編). 65・637. 3002-3007 (1999)

Masahito Shimada、Yoichiro Matsumoto、Takashi Kobayashi：“气泡核分布对云空化塌陷行为的影响”日本机械工程学会会刊（ed.B）3002-3007（1999）。

田村善昭,杉山和靖,松本洋一郎: "キャビテーション流れの数値計算法"次世代超音速旅客機成立のための空力基盤研究シンポジウム講演論文集. 27-31 (2001)

田村义明、杉山和康、松本阳一郎：《空化流的数值计算方法》下一代超音速客机研制基础空气动力学研究研讨会论文集27-31（2001）。

Yoshiaki Tamura, Naoki Tsuchiya, Hideaki Koito and Yoichiro Matsumoto: "Numerical Simulation of Cavitating Flow around a Two-Dimensional Hydrofoil"Proc. 10^<th> Symposium on Cavitation. 59-62 (1999)

Yoshiaki Tamura、Naoki Tsuchiya、Hideaki Koito 和 Yoichiro Matsumoto：“二维水翼周围空化流的数值模拟”Proc。

島田 正仁: "クラウドキャビテーションの崩壊挙動に及ぼす気泡核分布の影響"日本機械学会論文集(B編). 65・637. 66-71 (1999)

Masahito Shimada：“气泡核分布对云空化崩溃行为的影响”日本机械工程学会会刊（ed.B）66-71（1999）。

杉山和靖,高木周,松本洋一郎: "LESによる微細粒子を含む壁面乱流の数値解析(粒子の運動に及ぼす流れのSGSモデルの効果)"日本機械学会論文集(B編). 66・641. 103-112 (2000)

Kazuyasu Sugiyama、Shu Takagi、Yoichiro Matsumoto：“使用 LES 对含有细颗粒的壁湍流进行数值分析（流动的 SGS 模型对颗粒运动的影响）”日本机械工程师学会会刊（编 B）66・641。 .103-112 (2000)