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THREE-DIMENSIONAL NUMERICAL SIMULATION AND PERFORMANCE STUDY OF AN INDUSTRIAL HELICAL STATIC MIXER

Khosravi Rahmani, Ramin
http://rave.ohiolink.edu/etdc/view?acc_num=toledo1103149825

Abstract Details

2004, Doctor of Philosophy in Engineering, University of Toledo, Engineering.
In chemical processing industries, heating, cooling and other thermal processing of viscous fluids are an integral part of the unit operations. Consequences of improper mixing include non-reproducible processing conditions and lowered product quality. Static mixers economically promote the mixing of flowing fluid streams. One typical static mixer, the helical static mixer, consists of left- and right-twisting helical elements placed at right angles to each other. The range of Reynolds numbers of practical flows for helical static mixers in industry is usually from very small values to not very large values (e.g., Re = 5,000). This thesis describes how static mixing processes of single-phase Newtonian and also non-Newtonian liquids can be simulated numerically and provides useful information that can be extracted from the simulation results. The Turbulent flow case is solved using the most common Reynolds Averaged Navier-Stocks (RANS) models as well as Large-Eddy Simulation (LES) turbulent flow model. The numerical simulation of the mixing in the helical static mixer has been performed via a two-step procedure. In the first step, the flow velocity (and the pressure) is computed. These values are then used as input to the next step. In the second step the particle trajectory in the flow field is calculated. At the entry of the pipe inlet, a large number of marker particles are uniformly distributed over half of the flow field. This represents a simplified model for diametrical feeding of the mixer with two liquids. Using different measurement tools, such as Residence Time Distribution (RTD) and Particles Distribution Uniformity (PDU), the performance of a six-element helical static mixer is studied. It is shown that the Reynolds number has a major impact on the performance of a static mixer. It is also shown that the performance of a helical static mixer is different for Newtonian and non-Newtonian fluids in non-creeping flows. Finally, heat transfer within a helical static mixer is investigated. The effects of different flow conditions on the performance of the mixer are studied. It is shown that the helical static mixer is more effective for low Reynolds number laminar flows.
Theo Keith (Advisor)
338 p.
Engineering, Mechanical
Static Mixer; Large-Eddy Simulation; RANS Turbulence Model; Non-Newtonian Fluid; Heat Transfer; LES Turbulence Model; Pseudo-plastic Fluid

Recommended Citations

Citations

  • Khosravi Rahmani, R. (2004). THREE-DIMENSIONAL NUMERICAL SIMULATION AND PERFORMANCE STUDY OF AN INDUSTRIAL HELICAL STATIC MIXER [Doctoral dissertation, University of Toledo]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1103149825

    APA Style (7th edition)

  • Khosravi Rahmani, Ramin. THREE-DIMENSIONAL NUMERICAL SIMULATION AND PERFORMANCE STUDY OF AN INDUSTRIAL HELICAL STATIC MIXER. 2004. University of Toledo, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=toledo1103149825.

    MLA Style (8th edition)

  • Khosravi Rahmani, Ramin. "THREE-DIMENSIONAL NUMERICAL SIMULATION AND PERFORMANCE STUDY OF AN INDUSTRIAL HELICAL STATIC MIXER." Doctoral dissertation, University of Toledo, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1103149825

    Chicago Manual of Style (17th edition)

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This open access ETD is published by University of Toledo and OhioLINK.