空化噪声特性实验研究

利用不同类型的轴对称头体和ＮＡＣＡ１６０１２翼型做了一系列空化噪声实验，得到轴对称头体在不同空化数及不同速度下的空化噪声谱及翼型在不同的攻角下的空化噪声谱．这一系列的噪声谱表明，各种轴对称头体的空化噪声总声级随空化数的减小而升高，但噪声谱形具有明显的相似形；翼型在片空化、泡空化和云雾空化状态下所辐射的噪声谱存在明显的差别．噪声总声级的变化较为复杂，由泡空化状态转换到片空化状态，空化数虽然减小，但总声级会突然降低．针对翼型在泡空化状态下所辐射噪声谱的特征，利用单空泡溃灭理论进行了尝试性的解释和说明．

Investigation on the Noise of Cavitation

The paper is concerned with a basic study of some kinds of axisymmetric headforms and NACA16012 foil's cavity noise. Measurements of the different flow pattern's noise spectra of headforms show that the total noise increases as the cavitation number becomes small. But there are many similarities among these shapes of the noise spectras. The foil experiment shows that the noise spectra of bubble cavitation, sheet cavitation, cloud cavitation are obviously different. The total noise changes complexly. When the bubble cavitation turns on the sheet cavitation, the total noise will reduce suddenly although the cavitation number becomes smaller. The theory of single bubble collapse is used to explain the noise spectra of foil bubble cavity.