Project Inflow Generator
The aim of the research project is the development of a novel structure-based method for the artificial synthesis of the turbulent speed and scalar fields and their validation. The development is based on the previous work of the applicant, in which the turbulent velocity fields at the inflow are generated with compact element carriers of the velocity (Turbulent Spots Method) or the vortex strength (Turbulent Vorton method). An extension of the method should take into account realistic anisotropic structures, which occur especially near the wall. The starting point of the expansion is the synthesis of artificial fields of fluctuating quantities with prescribed statistical properties up to the moments of the second order (autocorrelations, spectrum, integral lengths) and structural information. The method is not only applied to the speed fields, but is generalized for the scalar fields, taking into account the multifractal properties of the scalar dissipation rate. The goal is still to develop and apply the method for compressible flows. The corresponding validation calculations are based on canonical test cases of fluid mechanics and material and heat transfer (channel, boundary layer, free shear layer and jet mixer (confined jet)). As a result of the work, a significant improvement in the methods for generating inflow signals for turbulent flows, taking into account anisotropic structures, is expected. After completion of the project, a program module for the generation of temporally and spatially correlated inflow boundary conditions will be available for all LES working groups.