Numerical simulation of turbulent flow in an industrial helical static mixer

Abstract

Purpose

Fluid mixing plays a critical role in the success or failure of industrial processes which call for the addition of small quantities of chemicals to working fluid. This paper aims to describe how mixing processes of liquids in turbulent flow regime can be simulated numerically, present the flow pattern through a helical static mixer, and provide useful information that can be extracted from the simulation results.

Design/methodology/approach

The performance of a helical static mixer under turbulent flow conditions is numerically studied. The model solves the 3D Reynolds‐averaged Navier‐Stokes equations, closed with the Spalart‐Allmaras turbulence model, using a second‐order‐accurate finite‐volume numerical method. Numerical simulations are carried out for a six‐element mixer. Using a variety of predictive tools, mixing results are obtained and the performance of static mixer under turbulent flow condition is studied.

Findings

The upstream mixing elements increase the mixing more effectively compared to the downstream mixing elements; and also, the rate of mixing is higher in the regions close to the edges of mixing elements.

Practical implications

Static mixers have been widely used in the following industries: chemicals, food processing, heating, ventilation, and air conditioning, mineral processing, paints and resins, petrochemicals and refining, pharmaceuticals, polymers and plastics, pulp and paper, and water and waste treatment.

Originality/value

This paper fulfils an identified information need and offers practical help to an individual researcher in academia as well as industry.

Citation

Rahmani, R.K., Keith, T.G. and Ayasoufi, A. (2008), "Numerical simulation of turbulent flow in an industrial helical static mixer", International Journal of Numerical Methods for Heat & Fluid Flow, Vol. 18 No. 6, pp. 675-696. https://doi.org/10.1108/09615530810885515