Tubular, or ``soda straw'' speleothems are often observed in limestone caves, thanks to the precipitation of calcium carbonate in a natural environment. However, the very long timescales involved often make their study impractical (typical growth velocity 100 mum/yr !). A much faster analogue system of stalactite formation has been designed and investigated in the lab. It uses instead a saturated solution of liquid strontium hydroxyde, dripping in an atmosphere containing gaseous CO2, and forming centimeter-scale pendant elastic shells with a tubular shape within a few hours by precipitation of solid strontium carbonate at the interface with the atmosphere. The goal of this internship is to understand quantitatively the growth of in-lab tubular stalactites, using a combination of data analysis, analytical and numerical tools. Two broad research questions may be considered, depending on the intern's interests and preferences: (i) what determines the shape of the pendant elastic shells? (ii) what determines their growth velocity? as a function of relevant physical parameters: injection flow, injection needle diameter, CO2 concentration, CO2 diffusion constant, strontium hydroxyde viscosity, strontium carbonate stiffness, etc.