In gas turbines some parts are exposed to high temperatures from the combustion gases well above the melting threshold of the material. Therefore, advanced cooling techniques are used to protect the parts exposed to these gases. One such system is the film cooling, necessary to guarantee a safe working condition for the turbine high-pressure stages. It consists in the ejection of cold air on the surface of the parts to create an adiabatic layer of gas at lower temperature. A good prediction of the interaction between the mainstream and the coolant jet is important for the design of such advanced cooling system.