New manufacturing techniques such as three-dimensional (3D) printing have the potential to drastically transform the field of chemical engineering. Novel, complex reactor geometries can be created that were previously impossible or required dedicated facilities to make. Driven by process intensification and in combination with the power of supercomputers, the sky promises to be the limit for chemical reactor and reaction engineering. Therefore in this proposal research is focused on improving heat and mass transfer in reactors by avoiding unwanted flow patterns such as counterflow, backflow and jet flow. This should translate in longer reactor lifetimes, reduced fouling and higher selectivities for a range of different reactor designs by building on the knowledge of the applicant’s group in reactive flow simulation. However, the models used in these simulations require extensive and modular validation with unprecedented attention to detail. Essential is information about local flow patterns (by 2D and 3D particle image velocimetry) and the local heat transfer (by using Liquid) that will be obtained together with the Von Karman Institute. This information will feed the developed first-principles based models for single-phase flow that solve the basic set of conservation equations (Navier-Stokes), properly describe turbulence, and last but not least account for the detailed free-radical reactions relevant for combustion and pyrolysis in vortex and swirl flow reactors.