Papers by Keyword: Hydrodynamic Analysis

Abstract: For improving fast-start performance of underwater propeller, the robot fish with high maneuverability is developed using the fish-like swimming mode characterized by undulatory flexible body. Through observations of C-start in crucian carp, the kinematic model of fast-start in robot fish is set up. According to hydrodynamic analysis on unsteady effect of added mass and wake vortices, liquid reaction forces on bionic fish-body are derived. Based on simulation experiment of C-start, propulsive performance indexes including kinetic energy, power and propulsion efficiency are presented respectively. The research results can provide theoretical basis of raising propulsive efficiency of C-start in subsequent underwater experiments, and optimization design of robot fish.

Abstract: The average Reynolds equation and average clearance equation of circular translational polishing (CTP) under the quasi-stable mixed lubrication state are set up in polar coordinates. The distributions of fluid pressure and contact pressure during polishing are numerically analyzed by solving simultaneously these equations along with the contact pressure equation. The effects of various process parameters on hydrodynamic performance of CTP are analyzed. By comparing the distributions of periodic average pressure along radial direction under fully and partially lubricated states, we conclude that carefully controlled CTP under mixed lubrication is beneficial to improving the surface quality and planarity of the wafer.