Based on integral equation method, the study of unsteady supercavitating flow past cones is presented. The shape and length of supercavity are calculated respectively using the finite difference time discretization me...Based on integral equation method, the study of unsteady supercavitating flow past cones is presented. The shape and length of supercavity are calculated respectively using the finite difference time discretization method. The characteristics of the shape and length of supercavities, which vary with the cone＇s angle and cavitation number, are investigated respectively, the varied features of some supercavity scales are analyzed when the flow field is perturbed periodically. The curves relationship between cavity length and cavitation number, which are based respectively on present method and other theories, are discussed and compared. It is obviously shown that the supercavity changes have two characteristics： retardance and wave. These results obtained would be useful in the case of design and analysis of cavitator under water.展开更多
The stability of wall bounded fibre suspensions was studied. The linear stability analysis was performed applying the flow stability theory and slender body theory. The results of numerical analysis show that fibres...The stability of wall bounded fibre suspensions was studied. The linear stability analysis was performed applying the flow stability theory and slender body theory. The results of numerical analysis show that fibres and their hydrodynamic interactions reinforce the flow stability. Investigation of fibre orientation and vorticity in the suspension revealed the mechanisms behind the instability. Drag reduction properties in the transition regime were also presented. The experiments using dye emission and PIV techniques verified theoretical results.展开更多
基金Project supported by the National Nature Science Foundation of China (Grant No:10572045) and Distinguished Young Scholar Science Foundation of Heilongjiang Province of China(Grant No: JC-9)
文摘Based on integral equation method, the study of unsteady supercavitating flow past cones is presented. The shape and length of supercavity are calculated respectively using the finite difference time discretization method. The characteristics of the shape and length of supercavities, which vary with the cone＇s angle and cavitation number, are investigated respectively, the varied features of some supercavity scales are analyzed when the flow field is perturbed periodically. The curves relationship between cavity length and cavitation number, which are based respectively on present method and other theories, are discussed and compared. It is obviously shown that the supercavity changes have two characteristics： retardance and wave. These results obtained would be useful in the case of design and analysis of cavitator under water.
文摘The stability of wall bounded fibre suspensions was studied. The linear stability analysis was performed applying the flow stability theory and slender body theory. The results of numerical analysis show that fibres and their hydrodynamic interactions reinforce the flow stability. Investigation of fibre orientation and vorticity in the suspension revealed the mechanisms behind the instability. Drag reduction properties in the transition regime were also presented. The experiments using dye emission and PIV techniques verified theoretical results.
