Observations and Measurements on Unsteady Cloud Cavitation Flow Structures

9th International Symposium on Cavitation

Gu, L.X.^1 ; Yan, G.J.^1 ; Huang, B.^2

Beijing Institute of Astronautical System Engineering, Beijing

100076, China^1

Beijing Institute of Technology, Beijing

100081, China^2

关键词: Dynamic characteristics;    Dynamic measurement system;    Experimental evidence;    High speed video cameras;    Observations and measurements;    Particle image velocimetries;    Turbulent velocity fluctuations;    Unsteady characteristics;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/656/1/012154/pdf
DOI  :  10.1088/1742-6596/656/1/012154

来源: IOP

【 摘 要 】

The objectives of this paper are to investigate the unsteady structures and hydrodynamics of cavitating flows. Experimental results are presented for a Clark-Y hydrofoil, which is fixed at α=0°, 5° and 8°. The high-speed video camera and Particle Image Velocimetry (PIV) are applied to investigate the transient flow structures. The dynamic measurement system is used to record the dynamic characteristics. The cloud cavitation exhibits noticeable unsteady characteristics. For the case of α=0°, there exit strong interactions between the attached cavity and the re-entrant flow. While for the case of α=8°, the re-entrant flow is relatively thin and the interaction between the cavity and re-entrant flow is limited. The results also present that the periodic collapse and shedding of the large-scale cloud cavitation, which leads to substantial increase of turbulent velocity fluctuations in the cavity region. Experimental evidence indicates that the hydrodynamics are clearly affected by the cavitating flow structures, the amplitude of load fluctuation are much higher for the cloud cavitating cases.