This research has investigated the above-mentioned process resulting in cavitation erosion step by step.

本研究逐步研究了上述导致空蚀的过程。

• 批准号: 09450372
• 负责人: KATO Hiroharu
• 金额: $ 9.02万
• 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: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09450372/
• 关键词: cavitation; Erosion; Prediction; Impact Pressure; Bubble Collapse; Sheet Cavitation; Cloud Cavitation; 壊食; クラウド; 気泡; 衝撃力; 蒸発; ホログラフィ

In terms of the total volume of sheet cavity, which turns into the total vapor volume of initial cloud cavity, it is necessary to know evaporation rate at the sheet cavity surface which is vapor/liquid interface. Thus, the evaporation rate at cavity surface has been predicted by measuring the temperature distribution along a sheet cavity generated in high temperature and high pressure water where the thermodynamic effect due to evaporation appears more clearly.Using a high speed video, the whole cavity behavior has been observed in detail. The frequency of cloud cavity shedding and the size and shape of the clouds have been measured. Also, a laser holography technique has been applied to measure the number and size of the bubbles in a could cavity.Cavitation impact force sensors developed and fabricated by ourselves have been used to measure the impactive forces due to collapse of cloud cavities. A high speed video has been taken at the same time with frame rate of 40,500 fps. Behavior of cloud cavity collapse has been investigated in detail with correlation to the time history of the impact force taken into account.

在将片腔的总体积转化为初始云腔的总蒸汽体积时，需要知道片腔表面即气/液界面处的蒸发速率。通过测量在高温高压水中形成的片状空腔的沿着温度分布，预测了空腔表面的蒸发速率，并利用高速摄像机详细观察了整个空腔的行为。云腔脱落的频率和云的大小和形状已被测量。利用激光全息技术测量了云腔内气泡的数量和大小，并利用自行研制的空泡冲击力传感器测量了云腔溃灭时的冲击力。同时拍摄了一段高速视频，帧速率为40，500 fps。云腔崩溃的行为进行了详细的研究与相关的时间历史的冲击力考虑在内。

项目成果

Yasutaka Kawanami, Hiroharu Kato, Hajime Yamaguchi, Masatsugu Maeda: "Bubble Distribution in a Cloud Cavity" Proc.9th Symposium on Cavitation, Sendai, 1997. 131-134 (1997)

Yasutaka Kawanami、Hiroharu Kato、Hajime Yamaguchi、Masatsugu Maeda：“云腔中的气泡分布”Proc.9th Symposium on Cavitation，仙台，1997。131-134（1997）

金野祥久,加藤洋治,他: "キャビテーション壊食量の推定法(第2報 : 気泡群崩壊による衝撃力頻度分布計測の信頼性評価)" 日本造船学会論文集. 184号. 15-26 (1998)

绀野义久、加藤洋二等：“气蚀量的推定方法（第2次报告：气泡群破裂的冲击力频率分布测量的可靠性评价）”日本造船学会会刊第184号。 15-26（1998）

Hiroharu Kato: "Complex Structure on Sheet-Cloud Cavitation" Proc.8rd Intern.Conf.on Pumps and Fans, Tsinghua University, Beijing. 1-12 (1998)

Hiroharu Kato：“片云空化的复杂结构”Proc.8rd Intern.Conf.on Pumps and Fans，清华大学，北京。

多賀谷義典,加藤洋治,他: "キャビティ内温度降下量の計測" 第9回キャビテーションに関するシンポジウム講演論文集. 83-86 (1997)

Yoshinori Tagaya、Yoji Kato 等人：“空腔内温度下降的测量”第九届空化研讨会论文集 83-86 (1997)。

Y.Kawanami,H.Kato,et al.: "Three-Dimensional Characteristics of the Cavities Formed on a Two-Dimensional Hydrofoil" Proc.3rd Int.Symp.on Cavitation, Grenoble. Vol.1. 191-196 (1998)

Y.Kawanami、H.Kato 等人：“二维水翼上形成的空腔的三维特征”Proc.3rd Int.Symp.on 空化，格勒诺布尔。