Simulating the recovery of sunken objects by blowing the pontoon by a controllable solid fuel gas generator

A mathematical model of raising sunken subjects using a pontoon blown by a controlled open gas generator (OG) with the possibility of temporary termination of its operation and the subsequent start is developed.
It is supposed that the pontoon has a cylindrical shape flown by a transverse water flow. Inside it, the OGs providing the blowing in the slugging regime are positioned. The volume flow from the tank into the environment was calculated by Bernoulli’s equation. The heat exchange of combustion products with water and the tank wall was taken in the form of Newton. The task was reduced to a system of nonlinear ordinary differential equations representing the energy balance relations for the mass and energy of combustion products filling the variable volume; equations modeling the layer-by-layer combustion of the solid fuel and the flow of water from the ballast tank; and the closing equation of state of an ideal gas and dependences of the internal ballistics of the gas generators. The dependence of the linear speed of burning on pressure was accepted in the form of a power law. The considered pontoon–cargo system was replaced by a material point. Calculating the speed of its ascent was carried out by integrating the equation of nonuniform rectilinear motion of a rigid body in a viscous incompressible fluid.
In the course of the parametrical analysis, it was found that at the stage of water replacement from the ballast tank the OG can be stopped repeatedly for some seconds. After achieving the carrying power necessary to provide the beginning of emersion of the pontoon–cargo system, it is possible to disconnect the open gas generator. The proposed actions will allow one to reduce the solid fuel consumption for carrying out the operation.