Saint-Gobain designs, produces and markets mineral insulation materials such as stone wool, which bring comfort and thermal performance to buildings, vehicles and infrastructure. The materials that make up rock wool can be melted using several types of furnace technologies before being fibered into wool. Some of these technologies involve coupled phenomena between flame jets and molten rock baths, which can trigger hydrodynamic instabilities. These instabilities represent a challenge for the regular conduct of the process, which is why it is necessary to acquire a detailed understanding of the physics of the stirred glass bath. In industrial furnaces, the presence of multiple injectors can lead to couplings between submerged jets. The objective of the internship is to investigate these interactions and the overall system dynamics using an experimental setup with three air jets injected into a water bath.