In solid propellant rocket motors incorporating a submerged nozzle, the entrapment of liquid residues of the combustion in the cavity formed in the surrounding of the nozzle integration part can lead to the accumulation of slag with a considerable mass.The long-term goal of the present study is to characterise experimentally the driving parameters of the slag accumulation in a stagnant area modelling the nozzle cavity. The experimental database will be used for validation of a numerical tool.In the present article measurements are shown in two-phase flow condition using a coldgas simplified model to determine effectively the main parameters that are influencing the droplet entrapment. Furthermore, the deformation of the accumulated liquid surface is analysed and presented as well.