Parametric study of the turbulent flow inside a spherical jet stirred reactor

Due to the importance of the kinetics of gas-phase chemical reaction in low-emission combustion, stirred tank reactors have been used for decades as the experimental tool of many investigations. A Jet Stirred Reactor (JSR) can be used to study the evolution of species mole fractions, while it provides efficient mixing by turbulent jets. However, it is important that the JSR is designed such that the concentration field is as homogeneous as possible in order to avoid disturbance of the chemical kinetics by inhomogeneities. In this work, numerical simulations were performed to investigate the effects of the geometrical parameters and the thermodynamic conditions on a JSR's mixing characteristics; i.e., the diameter of the spherical chamber was modified together with the diameter of nozzle. The turbulent structures inside the JSR and the nozzle tubes at microscales are captured using Large Eddy Simulations. The accuracy of the numerical results is demonstrated through a comparison of the residence time distribution (RTD) with a previous experimental study of tracer-decay technique. The results derived by RTD show that using a JSR with a diameter of 40 mm and a nozzle diameter of 1 mm, creates a nearly perfectly mixed composition and accordingly, behaves similar to an ideal reactor.