Modelling and Simulating Ballast Tank Blowing and Venting Operations in Manned Submarines

The aim of this work is to obtain mathematical models for both the blowing and venting of ballast tanks, as well as the effect of these operations over the submarine behavior. Although tanks are usually blown only on emergency situations, blowing and venting can potentially be used as a suitable control mechanism for specific manoeuvres, not only in submarines but in any marine system using ballast tanks, like offshore facilities or pontoon docks. We propose mathematical models for blowing and venting that are coupled with a 6 degree–of–freedom model for the equations of motion. All resulting equations are solved altogether thus obtaining a solution for the submarine behavior taking into account the effect of the mass change. In order to explore the potential of these operations as a control mechanism, results of a computer simulation are presented in which the submarine performs a depth change manoeuvre by only blowing and venting its ballast tanks without any use of diving planes.