Study on the chaotic mixing characteristics in an endogenous tree cut impeller stirred tank reactor

The impeller with fractal endogenous tree arrangement cuts design was introduced in the laminar mixing to facilitate chaotic advection. The chaotic mixing characteristics in an endogenous tree cut impeller (ETC) stirred tank were studied using experimental methods and numerical modeling. The results showed that the endogenous tree cut impeller led to a decrease in power consumption, power number, mixing time, and the dimension of isolated mixing regions (IMRs), an improvement in the chaotic mixing degree and the dimension of chaotic mixing regions (CMRs), and these phenomena became increasingly significant as the iteration count of cuts in the impeller blades rose. Moreover, Poincaré section and stretching field provided an effective means to uncover the IMRs and CMRs in the flow field, with these insights being confirmable via visualization experiments. The results of massless particle tracking suggested that the fractal endogenous tree arrangement cuts design of impeller blades could facilitate the escape of fluid particles from the IMRs to the CMRs and promote the continuous stretching and folding of fluid particles.