Confined impinging-jets reactors (CIJR) offer many advantages for tire chemical processing of rapid processes, such as precipitation and the production of organic nanoparticles. Nevertheless, due to the lack of predictive design criteria, the use of such a reactor for a new process currently requires a significant experimental campaign before it can be used commercially. Experimentally derived scale-up rules for CIJRs have recently been reported. Using carefully controlled experiments with a fast parallel-reaction system, the conversion of 2,2-dimethoxypropane (DMP) for a wide range of jet Reynolds numbers have been measured. The experimental conversion data call be accurately predicted using computational fluid dynamics (CFD) for the range of jet Reynolds number where the flow is turbulent. In addition, the CFD provides a wealth of detailed information on the reacting flow inside of the CIJR. Such information provides excellent guidance for improving the performance of the reactor by, for example, changes in the geometry. By clearly illustrating the ability of CFD to reproduce (without adjustable parameters) the experimental data for a CIJR, this study makes a significant step in the direction of "experiment-free" design and scale-up of chemical reactors.