Unravelling flow dynamics and mixing efficiency in a cubic stirred tank

¹ AGH University of Krakow, Faculty of Civil Engineering and Resource Management, Mickiewicza 30, 30-059, Kraków, Poland
² AGH University of Krakow, Faculty of Energy and Fuels, Mickiewicza 30, 30-059 Kraków, Poland

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Published online: 12 March 2026

Abstract

Fluid mixing is essential in numerous industrial sectors, including chemical manufacturing, food processing, and wastewater management. Achieving effective mixing promotes uniform distribution of components, accelerates reaction kinetics, improves final product quality, and reduces operational energy consumption. The effectiveness of mixing operations is influenced by fluid properties, vessel geometry, and impeller design, which together determine flow patterns and mass transfer dynamics. In this research study, two jet-type impeller configurations were investigated in a cubic vessel through a combination of Computational Fluid Dynamics and Particle Image Velocimetry. The numerical models were validated against experimental measurements, allowing for the benchmarking of key indicators such as flow topology and mixing quality indices. The investigation covered multiple parameters, including impeller geometry and fluid properties. Two fluids with different viscosities were analyzed to assess the adaptability of each impeller design to varying different process conditions. The study emphasizes the influence of geometric and operational parameters on velocity distribution in a cubic stirred tank. The integrated experimental-numerical approach provided a comprehensive evaluation of hydrodynamic behavior, offering practical insight for optimizing energy-efficient mixing systems. The results demonstrated that impeller geometry substantially influences fluid motion, with a higher blade angle promoting more uniform mixing patterns, albeit at the cost of higher torque and energy demand.