| Popis: |
An important parameter to submarine navigation and control is determining the hull speed relative to the surrounding sea. The object of this paper is to find possible locations for speed sensors on a submarine. The probes should be fitted to the hull areas where the water flow is free of turbulence structures, vortices, or bubble formation to obtain a reliable measurement. In this work, a rational procedure is proposed to identify the probe installation site on the hull of the DARPA SUBOFF-5470 submarine, through numerical simulations using OpenFOAM. Three different depth conditions at three different navigation speeds were considered to assess the free-surface effect. First, verification and validation procedures were completed at deep water conditions (H/D = 5.4). The results of this analysis indicate a convergence ratio of 0.49 with an uncertainty of 0.04%SC. Later, a grid convergence analysis was completed at periscope depth conditions (H/D = 1.1), within the highly nonlinear Froude range. These results show an oscillatory convergence with an uncertainty of 0.78%. Finally, the hull region between 5 and 15% from the bow of the submarine length is recommended for installing the speed probe, considering the linearity of the flow, without high gradients and vortex structures. |
