Journal ArticleDOI
CFD calculation of turbulent flow with arbitrary wall roughness
TLDR
In this paper, a wall function for arbitrarily rough surfaces is developed in detail and its ability to reproduce the Darcy friction factor in rough-walled pipes is tested, and the application of the wall function to the Reynolds-stress transport equations and modifications for streamwise pressure gradient are also discussed.Abstract:
Wall functions are used in CFD calculations of turbulent flow to handle the no-slip boundary condition at solid surfaces without an unacceptably-large number of grid cells. Recent work in the Turbulence Mechanics Group at the University of Manchester has been aimed at developing wall functions suitable for non-equilibrium flows – primarily for smooth walls. For environmental fluid-mechanics problems, however, there is a need to extend the new wall-function concepts to arbitrary wall roughness. Suga, Craft and Iacovides (Extending an analytical wall function for turbulent flows over rough walls, 6th International Symposium on Engineering Turbulence Modelling and Measurements, Sardinia, 2005) have shown how this may be achieved by making the zero-eddy-viscosity height, yν, a function of roughness. Their function is, however, largely empirical, and this paper goes further by demonstrating that the zero-eddy-viscosity height can be more satisfactorily determined by appealing to higher-order consistency with the log law. Roughness-dependent changes are also made to the near-wall prescription of the turbulent kinetic energy dissipation rate, e. The wall function for arbitrarily-rough surfaces is developed in detail and its ability to reproduce the Darcy friction factor in rough-walled pipes is tested. Some computational results for the more complex application which stimulated this work – sediment transport and sandbank morphodynamics – are then given. The application of the wall function to the Reynolds-stress transport equations and modifications for streamwise pressure gradients are also discussed.read more
Citations
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Journal ArticleDOI
Predicting the effect of biofouling on ship resistance using CFD
TL;DR: In this paper, a Computational Fluid Dynamics (CFD) based unsteady RANS model which enables the prediction of the effect of marine coatings and biofouling on ship resistance and effective power was presented.
Journal ArticleDOI
Limiters and wall treatments in applied turbulence modeling
TL;DR: In this paper, the authors provide a review of the use of turbulence models in practical use of wall and outer region models, including large strain limiters, wall functions and roughness corrections.
Journal ArticleDOI
Investigating the effect of biofouling on propeller characteristics using CFD
TL;DR: In this article, the effects of biofouling on the performance of Potsdam Propeller Test Case (PPTC) propeller using Computational Fluid Dynamics (CFD) were investigated.
Journal ArticleDOI
Computational Fluid Dynamics Simulation of Fouling on Axial Compressor Stages
TL;DR: In this paper, the effect of fouling on axial compressor performance was investigated by means of a commercial computational fluid dynamic code (CFD) and the numerical model was validated against the experimental data available from literature.
References
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Book
Boundary layer theory
TL;DR: The flow laws of the actual flows at high Reynolds numbers differ considerably from those of the laminar flows treated in the preceding part, denoted as turbulence as discussed by the authors, and the actual flow is very different from that of the Poiseuille flow.
Journal ArticleDOI
The numerical computation of turbulent flows
Brian Launder,D. B. Spalding +1 more
TL;DR: In this paper, the authors present a review of the applicability and applicability of numerical predictions of turbulent flow, and advocate that computational economy, range of applicability, and physical realism are best served by turbulence models in which the magnitudes of two turbulence quantities, the turbulence kinetic energy k and its dissipation rate ϵ, are calculated from transport equations solved simultaneously with those governing the mean flow behaviour.
Journal ArticleDOI
Progress in the development of a Reynolds-stress turbulence closure
TL;DR: In this article, the authors developed a model of turbulence in which the Reynolds stresses are determined from the solution of transport equations for these variables and for the turbulence energy dissipation rate E. Particular attention is given to the approximation of the pressure-strain correlations; the forms adopted appear to give reasonably satisfactory partitioning of the stresses both near walls and in free shear flows.
Formulas for Bed-Load transport
E. Meyer-Peter,R. Müller +1 more
TL;DR: In this article, an attempt is made to derive an empirical law of bed-load transport based on recent experimental data and the results and interpretation of tests already made known in former publications of the Laboratory for Hydraulic Research and Soil Mechanics at the Federal Institute of Technology, Zurich.
Journal ArticleDOI
On the calculation of turbulent heat transport downstream from an abrupt pipe expansion
C. C. Chieng,Brian Launder +1 more
TL;DR: In this paper, the authors reported a numerical study of flow and heat transfer in the separated flow region created by an abrupt pipe expansion and employed an adaptation of the TEACH-2E computer program with the standard model of turbulence.