Browsing Research Output by Author "10184600 - Du Toit, Charl Gabriel De Kock"
Now showing items 1-20 of 46
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Accounting for porous structure in effective thermal conductivity calculations in a pebble bed reactor
Van Antwerpen, W.; Rousseau, P.G.; Du Toit, C.G. (Atomic Energy Society of Japan, 2009)A proper understanding of the mechanisms of heat transfer, flow and pressure drop through a packed bed of spheres is of utmost importance in the design of a high temperature pebble bed reactor. A thorough knowledge of the ... -
Analysing the porous structure of packed beds of spheres using a semi-analytical approach
Du Toit, Charl G. (Elsevier, 2019)In this paper methodologies are described for the analysis of the porous structure of cylindrical and annular packed beds consisting of spheres when the coordinates and sizes of the spheres are known. Methodologies to ... -
Analysis of the porous structure of an annular pebble bed reactor
Du Toit, C.G.; Van Antwerpen, W.; Rousseau, P.G. (Atomic Energy Society of Japan, 2009)This paper discusses the numerical analysis of the porous structure of an annular packed bed. Numerical procedures are described to determine the variation in the porosity, the variation in the coordination number (measure ... -
Analysis of the porous structure of packed beds of spheres using computed X-ray tomography
Du Toit, C.G.; Rosslee, P.J. (SAAM, 2012) -
Benchmarks for the validation of the heat transfer capabilities of one-dimensional system codes
Du Toit, Charl G. Jat; Niemand, Peter F.; Tak, N.I.; Kim, M.H. (Begell House, 2019)The purpose of the reactor cavity cooling system in a nuclear plant is to effectively remove the heat released by the reactor pressure vessel. The reactor cavity cooling system must be able to operate safely in a natural ... -
CFD analysis of thermal dispersion in a structured packed bed
Vermaak, H.J.; Du Toit, C.G. (SACAM, 2018)Packed beds are generally modelled in a partial manner to avoid computational costs. This implies that only a small portion of the representative bed is modelled explicitly in CFD simulations, usually by assuming ... -
CFD and systems thermal-hydraulic analysis in the design and safety assessment of high-temperature reactors
Rousseau, Pieter G.; Du Toit, Charl G.; Van Antwerpen, Herman J. (Woodhead Publishing, 2019)An overview is provided of the role of the various levels of CFD in the different stages of the design, analysis and evaluation of very-high-temperature reactor (VHTR) systems and molten salt reactor (MSR) systems. The ... -
Code-to-code comparison for analysing the steady-state heat transferand natural circulation in an air-cooled RCCS using GAMMA+ and Flownex
Rousseau, P.G.; Du Toit, C.G.; Jun, J.S.; Noh, J.M. (Elsevier, 2015)The GAMMA+ and Flownex codes are both based on a one-dimensional flow network modelling approach and both can account for any complex network of different heat transfer phenomena occurring simultaneously. However, there ... -
Comparison between Flownex and CORONA thermal-hydraulic models for a single HTR prismatic fuel assembly
Khoza, S.N.; Du Toit, C.G.; Rousseau, P.G.; Lee, S.N. (ANS (American Nuclear Society), 2016) -
Conservation of scattered energy and asymmetry factor in the new Rotationally Symmetric Spherical Discretisation scheme
Roos, T.H.; Du Toit, C.G.; Harms, T.M. (Elsevier, 2016)A Rotationally Symmetric Spherical Discretisation (RSSD) technique has recently been developed for the discretisation of scattering phase functions in the Discrete Ordinates Method (DOM) in a consistent and rational manner. ... -
Effect of reactor vessel cooling insulation and reflector heat pipes on the temperatures of a pebble-bed reactor using a system CFD approach
Du Toit, C.G.; Van Antwerpen, H.J. (Elsevier, 2020)This study investigates firstly, the effects of varying insulation thickness and flow path width between the core barrel and RCCS-concrete pressure vessel of an upward-flow helium-cooled pebble bed HTGR. The effects on ... -
The evaluation of 3D CFD approaches to model the flow and heat transfer inside an unstructured bed of uniform spheres
Potgieter, M.C.; Du Toit, C.G.; Kruger, J.H. (SACAM, 2016) -
Evaluation of the Berman-Olander long-bowl gas centrifuge solution
Du Toit, C.G.; Mercurio, G. (Taylor & Francis, 2015)The hydrodynamic equations for a long-bowl gas centrifuge can be simplified to obtain a one-dimensional differential equation for the variation of the non-dimensional axial velocity in the radial direction. In this study ... -
Experimental investigation of the effective thermal conductivity in the near-wall region of a packed pebble bed
De Beer, M.; Du Toit, C.G.; Dreyer, H. (SACAM, 2016) -
Experimental study of the effective thermal conductivity in the near-wall region of a packed pebble bed
De Beer, M.; Du Toit, C.G.; Rousseau, P.G. (Elsevier, 2018)The effective thermal conductivity is an important parameter that represents the overall heat transfer in packed beds, including packed pebble beds. Experimental test facilities have been used to determine the effective ... -
The extraction of the temperature gradient from measured temperature profiles with uncertainty propagation, as applied to the high temperature test unit
Van Antwerpen, H.J.; Rousseau, P.G.; Du Toit, C.G. (SAAM, 2010)This paper highlights the usefulness of applying analytical methods for uncertainty analysis to a least-squares polynomial fit. It also presents an equation to calculate the confidence interval in the slope of a regression ... -
Finite element solution of fully developed non-isothermal laminar flow in annuli
Du Toit, C.G. (SACAM, 2010) -
The flow and heat transfer in a packed bed high temperature gas-cooled reactor
Du Toit, C.G.; Rousseau, P.G. (ASME, 2010)Engineers are faced with two major challenges when carrying out the thermal-fluid design of a complex system consisting of many interacting components such as the PBMR power plant. The first challenge is to predict the ... -
Fluid flow distribution above an annular bed of randomly packed spheres
Reyneke, H.J.; Du Toit, C.G. (SAAM, 2010) -
Formulation of a unit cell for a thermal-hydraulic systems model of a prismatic fuel block of a high temperature gas-cooled reactor
Khoza, S.N.; Du Toit, C.G.; Rousseau, P.G. (SACAM, 2016)