The optimization method of transient hydrodynamic calculation model for extendable manipulators

Abstract

This research addresses the challenges in transient hydrodynamic modeling posed by the unique structure of extendable manipulators and the variation of the surrounding flow field, proposing an optimized hydrodynamic calculation model based on flow separation characteristics. To achieve this, transient Computational Fluid Dynamics (CFD) simulations are conducted, enabling the acquisition of true hydrodynamic data for the manipulator during extension. Analysis of this data reveals calculation errors in traditional single-rod models at specific angles of incidence (the angle between the rods and incoming flow), underscoring the need for model optimization. By examining flow characteristics maps, regions exhibiting significant blockage effects are identified, which informs the development of an enhanced model grounded in the Morrison equation to accurately capture hydraulic effects in these areas. To simplify the complexity of calculating multiple hydrodynamic coefficients simultaneously in optimized model, the equivalent drag coefficient method is introduced to further refine the drag calculations, culminating in an optimized hydrodynamic calculation model for manipulators. Comparison of the optimized model’s predictions with experimental data demonstrates its accuracy and applicability, supported by analyses of the equivalent drag coefficient across various flow field conditions and angles of incidence.