Computation of Dynamic Stability and Control Derivatives

摘要

The objective of this research is to devebp a predictive technology to support virtual design and evaluation of underwater vehicles systems, employing a Computational Fluid Dynamics (CFD) based methodology for predicting stability and control derivatives. Computational Fluid Dynamics technology coupled with modeling and control system design will allow vehicle conceptual designs to be evaluated within the context of a realistic mission. The preliminary goal of this effort is to estimate stability and control derivatives of underwater vehicles from CFD data as an evaluation of the potential for this method to replace/reduce expensive experimental (ie. tow-tank) tests. The need to establish a predictive capability technologies to support virtual design and evaluation of underwater vehicles systems, presented an opportunity to apply a multiblock, structured-grid, incompressible Navier-Stoke flow solver referred to as Tenasi, which have evolved over many years. The solver utilizes a state-of-the-art implicit upwind numerical scheme to solve the time-dependent Navier-Stokes equations in a generalized time-dependent curvilinear coordinate system. The numerical studies were performed for two underwater configurations to validate the accuracy and reliability of the present software tooL The computed results show favorable agreement with experimental data. The results from this study are very encouraging and strongry suggest that further development and application of this tool to more complicated underwater and high-speed supercavitating vehicles is needed. The results of this tool can be used to improve the performance of autonomous underwater vehicles. Methodologies and software tools are developed here that utilize vehicle-maneuvering simulated results to directly estimate standard hydrodynamie model coefficients, which are used for high-fidelity simulations and control system design.