Enhancement of mixing performance with anchor-type impellers via chaotic advection

Abstract

An asymmetric anchor impeller was proposed to improve mixing performance of anchor-type impellers by reducing unmixed regions, where materials transport is limited. Dynamical structures of various anchor-type impellers were analyzed systematically with numerical Poincare sections and flow visualiza-tion. Design parameters of basic anchor-type impellers, such as the blade width, the position and width of the support beam, and the presence of the bottom blade were investigated, along with comparison to dynamical systems formed by the standard anchor impeller. An optimal design was selected by incorpo-rating two basic type impellers having a large difference in dynamical systems. The optimal impeller was composed of two different half impellers, which was found to improve the materials transport via the streamline crossing mechanism. The total power draw required for agitation was also found a bit lower in the optimal asymmetric anchor impeller than that in the standard one. (c) 2021 Elsevier Ltd. All rights reserved.