As in the current industrial process, mixing is an essential process for various streams of application in engineering fields. The aim of this paper is to predict flow behaviour of the mixing process in mixing tank with the Rushton impeller and find out the best suitable design that creates required turbulence for producing a better degree of homogeneity in mixing. The rotation of the impeller is modelled using MRF in a single-phase medium treating the walls with a no-slip boundary. The mixing characteristics of single and multiple impellers are investigated by varying the impeller speeds and the results of velocity and pressure contours are compared to identify the best impeller with enhanced mixing. © 2021 Institute of Physics Publishing. All rights reserved.