The subject of this research is the development of a digital twin for the process of mixing the components of a gas mixture in the mixer of a mixture generator. The problem is motivated by the concept of digitalizing modern production and is considered in relation to the technology in question for generating a gas mixture of a given composition and homogeneity. A gas-dynamic model of an unsteady flow has been constructed and a numerical study carried out using the Ansys Fluent software. The Reduced Order Model was developed and used in the Ansys Twin Builder platform to build the digital twin.