# Difference between revisions of "UFR 3-35 Best Practice Advice"

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= Best Practice Advice = | = Best Practice Advice = | ||

== Key Physics == | == Key Physics == | ||

− | To cover this highly complex flow situation, a high spatial resolution is required for both the CFD as well as the experiment. The horseshoe vortex dynamics are driven by the downflow in front of the cylinder. This downward directed flow is caused by a vertical pressure gradient, which in turn depends on the shape of the approaching inflow profile. Therefore, to study the horseshoe vortex in detail and in a generic way, the development of a fully developed turbulent boundary layer approaching the cylinder should be ensured in the first place. Furthermore, the wall-shear stress is highly sensitive with respect to the spatial resolution of the data. To cover the strong velocity gradients, in particular of the the near-wall jet, high spatial resolution is required (<math> \ | + | To cover this highly complex flow situation, a high spatial resolution is required for both the CFD as well as the experiment. The horseshoe vortex dynamics are driven by the downflow in front of the cylinder. This downward directed flow is caused by a vertical pressure gradient, which in turn depends on the shape of the approaching inflow profile. Therefore, to study the horseshoe vortex in detail and in a generic way, the development of a fully developed turbulent boundary layer approaching the cylinder should be ensured in the first place. Furthermore, the wall-shear stress is highly sensitive with respect to the spatial resolution of the data. To cover the strong velocity gradients, in particular of the the near-wall jet, high spatial resolution in the range of the Kolmogorov length scale is required (<math> \Delta x \propto \eta_{\mathrm{K}}</math>). |

== Numerical Modelling Issues == | == Numerical Modelling Issues == |

## Revision as of 14:25, 29 August 2019

## Contents

# Cylinder-wall junction flow

## Underlying Flow Regime 3-35

# Best Practice Advice

## Key Physics

To cover this highly complex flow situation, a high spatial resolution is required for both the CFD as well as the experiment. The horseshoe vortex dynamics are driven by the downflow in front of the cylinder. This downward directed flow is caused by a vertical pressure gradient, which in turn depends on the shape of the approaching inflow profile. Therefore, to study the horseshoe vortex in detail and in a generic way, the development of a fully developed turbulent boundary layer approaching the cylinder should be ensured in the first place. Furthermore, the wall-shear stress is highly sensitive with respect to the spatial resolution of the data. To cover the strong velocity gradients, in particular of the the near-wall jet, high spatial resolution in the range of the Kolmogorov length scale is required ().

## Numerical Modelling Issues

### Discretisation method

### Grids and grid resolution

### Boundary conditions and computational domain

## Physical Modelling

### Turbulence modelling

### Transition modelling

### Near-wall modelling

### Other modelling

## Application Uncertainties

## Recommendations for Future Work

Contributed by: **Ulrich Jenssen, Wolfgang Schanderl, Michael Manhart** — *Technical University Munich*

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