The course deals with the turbulence, mathematical models of laminar and turbulent flow with heat transfer and incompressible compressible gases. For solution the software product ANSYS-CFX is applied, which uses finite volume integration method. The mathematical model is complemented by boundary and initial conditions. In detail the classic k-eps model is derived and other models are used, for example LES, SAS, DES models. To create geometry the data transfer between CAD - ANSYS-Workbench will be used. The theory is applied to examples of the basic fluid mechanics, buoyancy, natural convection and heat transfer.