3501. Simulation-based Transitional Stability Criteria for Submarines

Paper

Abstract

This paper documents the analysis of simulation-based submarine roll data pursuant to the development of new submarine stability criteria for the transition between submerged and surfaced conditions. A matrix of ship, environmental, and simulator conditions was developed resulting in 137 different run conditions, each of which was repeated 50 times for a period of 200 seconds at a sample rate of 1Hz. This resulted in 6850 data files and 1.37 million data points for each of the seventeen channels of data recorded (e.g., speed, depth, roll, pitch). The data was processed semi-automatically through a custom document process program designed by the author using the R statistical environment for statistical analysis and data graphics, and LATEX for typesetting detailed and summary reports for each condition and each run. This paper looks at roll angles only, and mainly for the most extreme 34 of the 137 conditions used in the simulation matrix (six conditions in lower sea states were also included). In Part I the effects of varying BG, inertia, depth and speed, wind, wave height, wave direction, phase, and sail configuration are analyzed in condition to condition comparisons. Part II proposes new transitional stability criteria based on traditional static stability calculations and also on dynamic roll probabilities based on the results of Part I. The static criteria is based on a minimum GM of 0.15 feet, minimum levels and times for stability restitution, and energy comparison. The dynamic criteria is based on the probabilities of exceeding 30, 45, and 60roll angles in beam seas corresponding to sea states 6, 7, and 8.