Numerical modeling of nature gas leakage from underwater gas pipeline

In the preprint we consider the simplified model problem of the release of the natural gas from the subsea pipeline. In the framework of a single equation of state, we perform mathematical modeling of a light gas (methane) outflow from a pipeline into the domain occupied by a heavier gas (water) that borders another light gas (air) along a plane. The problem is considered in the two-dimensional approximation that takes into account the plane and axial symmetries. The analysis of the flow appeared, and some peculiarities of the methane rising and entering the air are discussed; the estimation of the mass flow rate from the pipeline and methane releasing into air is given.