Masters Theses

Keywords and Phrases

Computational Fluid Dynamics (CFD); Detached Eddy Simulation (DES); Large Eddy Simulations (LES); Nozzle Clogging; Submerged Entry Nozzle (SEN); Turbulence

Abstract

"In this research, the measurements of clog deposit thickness on the interior surfaces of a continuous casting nozzle were compared with Computational Fluid Dynamics (CFD) predictions of melt flow patterns and particle-wall interactions to identify the mechanisms of nozzle clogging. A hybrid turbulent approach, Detached Eddy Simulation (DES), was configured to simulate both turbulent structures and particle-wall interactions inside the nozzle accurately. For experimental measurements of nozzle clogging, a nozzle received from industry was encased in epoxy and carefully sectioned to allow measurement of the deposit thickness on the internal surfaces of the nozzle. CFD simulations of melt flow patterns and particle-wall adhesion inside the nozzle were performed applying the geometry and operating conditions of the industrial test. The simulation results indicated that the hybrid DES model incorporates both advantages of Reynolds Averaged Navier-Stokes (RANS) and Large Eddy Simulation (LES) models which are suitable for modeling wall bounded and transient turbulent flows, respectively. Also, the CFD results showed that the convergent areas of the interior cross section of the nozzle increased the velocity and turbulence of the steel flow inside the nozzle, and decreased the clog deposit thickness locally in those areas. The simulations predicted a higher rate of attachment of particles in the divergent area between two convergent sections of the nozzle, which matched the observations made in the industrial nozzle measurements. Additionally, a mathematical model is proposed for adhesion of particles, to the nozzle wall. This model provides a particle-wall adhesion criterion by considering the presence of external forces, physical characteristics of both wall and particle (e.g. hardness, Young's modules), and the effect of internal forces (e.g. Van Der Waals)"--Abstract, page iv.

Advisor(s)

Asle Zaeem, Mohsen

Committee Member(s)

Smith, Jeffrey D.
O'Malley, Ronald J.

Department(s)

Materials Science and Engineering

Degree Name

M.S. in Materials Science and Engineering

Publisher

Missouri University of Science and Technology

Publication Date

Fall 2016

Journal article titles appearing in thesis/dissertation

  • Computational fluid dynamics study of molten steel flow patterns and particle-wall interactions inside a slide-gate nozzle by a hybrid turbulent model
  • Comparison of CFD simulations with experimental measurements of nozzle clogging in continuous casting of steels

Pagination

xi, 77 pages

Note about bibliography

Includes bibliographic references.

Rights

© Mahdi Mohammadi-Ghaleni

Document Type

Thesis - Open Access

File Type

text

Language

English

Library of Congress Subject Headings

Computational fluid dynamics -- Computer simulation
Continuous casting -- Mathematical models
Nozzles
Steel -- Metallurgy

Thesis Number

T 11043

Electronic OCLC #

974715597

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