Elliptical tanks were used as an alternative to circular tanks in order to improve mixing efficiency and reduce mixing time in unbaffled stirred tanks (USTs). Five different aspect ratios of elliptical vessels were designed to compare their mixing time and flow field. Computational fluid dynamics (CFD) simulations were performed using the

k

-

ε

model to calculate the mixing time and simulate turbulent flow field features

such as streamline shape

velocity distribution

vortex core region distribution

and turbulent kinetic energy (TKE) transfer. Visualization was also carried out to track the tinctorial evolution of the liquid phase. Results reveal that elliptical stirred tanks can significantly improve mixing performance in USTs. Specifically

the mixing time at an aspect ratio of 2.00 is only 45.3% of the one of a circular stirred tank. Furthermore

the secondary flow is strengthened and the vortex core region increases with the increase of aspect ratio. The axial velocity is more sensitive to the aspect ratio than the circumferential and radial velocity. Additionally

the TKE transfer in elliptical vessels is altered. These findings suggest that elliptical vessels offer a promisi

ng alternative to circular vessels for enhancing mixing performance in USTs.