MECHANISM OF TRANSFORMATION AND CONCENTRATION TO IMPULSIVE ENERGY FROM FLOW DYNAMIC ENERGY DUE TO CAVITATION

从空化发生点和冲击强度的控制和预测角度出发，对涡空化的发生机理和空化能量集中产生的高冲击进行了实验和数值研究，特别是对涡空化的高冲击机理、空泡溃灭行为和近壁及高压场中的冲蚀机理进行了研究，振动空化具有强烈的冲蚀性和空化泡的能量集中过程.为了弄清水的抗拉强度，通过计算机模拟和实验研究了文丘里型轴对称缩放喷管内的空化初生特性。2.对于内流型轴对称通道（如圆柱孔）中的分离涡空化，我们可以观察到一种重入流动和云状空化向涡腔下游方向的脱落。3.空化特性 ...更多信息 分离涡型空化在二维流场中的影响。对收敛-扩张通道进行了检查，以测量特别是在脱落涡腔崩溃时的强烈冲击。4.针对圆柱体和三角形圆柱体后产生的交替脱落型涡空蚀，讨论了空泡行为与空蚀冲击和冲蚀的关系。交替脱落涡空化与云状空化具有相似的空化方式。5.在振动装置和蝶阀中，在类似实际流动的流动条件下，进行了气穴冲击研究。结果表明，干涉对气泡间的高冲击以及压力场与气泡溃灭之间的高冲击有重要影响。6.利用超高速摄像机对压力波的传播现象进行了研究，以弄清气泡溃灭的原因。气泡的溃灭是通过压力波的传播以链式反应的方式引起的。少

The occurrence mechanism and high impact due to energy concentration due to cavitation are investigated experimentally and numerically from viewpoints of control and prediction of occurrence point and impact strength, especially, about such points as high impact mechanism of vortex cavitation, cavity collapsing behavior and erosion mechanism near solid wall as well as in high pressure field, vibratory cavitation with highly erosive characters and process of energy concentration due to cavitation bubbles.1. The characteristics of cavitation inception were investigated in an axial-symmetrical convergent-divergent nozzle of a Ventuli-type through computer simulation and experiments to make clear the tensile strength of water. 2. For separated vortex cavitation in an inner-flow type of axi-symmetrical channel such as a cylindrical orifice, we can observe a reentrant flow and a shedding of cloud cavitation toward the downstream direction of vortex cavity. 3. The characteristics of cavitatio … More n impacts of separated-vortex-type cavitation in a two-dimensional. Convergent-divergent channel were examined to measure strong impacts especially at the collapse of shedding vortex cavity. 4. The relationship of cavitation bubble behavior with cavitation impacts and erosion was discussed about an alternate shedding-type vortex cavitation caused behind a circular or triangular cylindrical body. The alternate shedding vortex cavitation shows a similar manner to the cloud-like cavitation. 5. A study of cavitation impact was made under the flow condition like an actual flow in a vibratory apparatus and a butterfly valve. The results show that the interference is important on the occurrence of high impact between neighboring bubbles and between the pressure field and the bubble collapse. 6. The propagation phenomenon of pressure wave was examined to make clear the cause of bubble collapse using an ultra-high speed video camera. The bubble collapse was caused in a chain-reaction manner through the propagation of pressure Wave. Less