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Klasson, O. (2011) A Validation, Comparison and Automation of Different Computational Tools for Propeller Open Water Predictions. Göteborg : Chalmers University of Technology (Report. X - Department of Shipping and Marine Technology, Chalmers University of Technology, Göteborg, Sweden, nr: 264).
BibTeX
@mastersthesis{
Klasson2011,
author={Klasson, Olof Klerebrant},
title={A Validation, Comparison and Automation of Different Computational Tools for Propeller Open Water Predictions},
abstract={Open water behaviour of a propeller is an important indication of the propeller performance.
This Master’s Thesis report describes the procedure for computing open water characteristics
using four different methods, how to measure velocity fields and how to predict cavitation for
a propeller in uniform inflow. The four methods were Computational Fluid Dynamics (CFD),
boundary element method, lifting line method and Wageningen Series. Further the report
describes how the methods were automated in means of computing open water characteristics
and how they compare to model test results. The objective with the project was to gain
knowledge about when the methods are preferred to use, what limitations they have and how
to minimize the work effort by means of automation of the tools. The benefit of setup
automation is not solely the time savings, but also the security in standardized setup methods.
This reduces the risk of setup errors in the results. Automatic post processing was developed
to some extent for the tools as well.
For the project, three different propeller geometries were used; one designed to generate a tip
vortex, one designed to reduce pressure pulses and one with a more conventional design. The
propeller designed to generate a tip vortex was part of the SMP’11 Workshop on Cavitation
and Propeller Performance. The SMP’11 Workshop was intended to give research groups the
possibility to validate their computational tools against both model tests and other software,
set up by different users. The workshop provided model test results of open water
characteristics, velocity field measurements and cavitation patterns. These test results were
predicted in this project and will also be included in the workshop. The other two propellers
were used to automate the four methods and validate them against model test results.
The CFD analyses were performed with the open source CFD toolbox OpenFOAM. Steady
Reynolds-Averaged Navier-Stokes (RANS) simulations with <i>k</i> − ωSST turbulence model
and wall functions in combination with Multiple Reference Frames (MRF) were used for the
CFD simulations. The grids and automatic CFD pre-processing were performed with the
commercial meshing software ANSA. The boundary element method predictions and grid
generation were performed in the CRS developed tool PROCAL. The lifting line method
predictions were performed in an Excel workbook with macros. The Wageningen Series
predictions came directly from the Wageningen polynomials. The three latter methods were
automated using visual basic and Excel.
One important conclusion is that CFD gives the most accurate predictions, but requires many
CPU-hours. When results are needed quickly, the boundary element method is useful and
accurate enough. The lifting line method generates less accurate results than the other
methods. The Wageningen Series is useful to give an indication of the predicted results
validity. The automated codes save hours of work and results in consequent setups.},
publisher={Institutionen för sjöfart och marin teknik, Fartygs framdrivning och miljöpåverkan, Chalmers tekniska högskola},
place={Göteborg},
year={2011},
series={Report. X - Department of Shipping and Marine Technology, Chalmers University of Technology, Göteborg, Sweden, no: 264},
keywords={Open water characteristics; CFD; Boundary element method; Lifting line method;},
note={94},
}
RefWorks
RT Generic
SR Electronic
ID 146813
A1 Klasson, Olof Klerebrant
T1 A Validation, Comparison and Automation of Different Computational Tools for Propeller Open Water Predictions
YR 2011
AB Open water behaviour of a propeller is an important indication of the propeller performance.
This Master’s Thesis report describes the procedure for computing open water characteristics
using four different methods, how to measure velocity fields and how to predict cavitation for
a propeller in uniform inflow. The four methods were Computational Fluid Dynamics (CFD),
boundary element method, lifting line method and Wageningen Series. Further the report
describes how the methods were automated in means of computing open water characteristics
and how they compare to model test results. The objective with the project was to gain
knowledge about when the methods are preferred to use, what limitations they have and how
to minimize the work effort by means of automation of the tools. The benefit of setup
automation is not solely the time savings, but also the security in standardized setup methods.
This reduces the risk of setup errors in the results. Automatic post processing was developed
to some extent for the tools as well.
For the project, three different propeller geometries were used; one designed to generate a tip
vortex, one designed to reduce pressure pulses and one with a more conventional design. The
propeller designed to generate a tip vortex was part of the SMP’11 Workshop on Cavitation
and Propeller Performance. The SMP’11 Workshop was intended to give research groups the
possibility to validate their computational tools against both model tests and other software,
set up by different users. The workshop provided model test results of open water
characteristics, velocity field measurements and cavitation patterns. These test results were
predicted in this project and will also be included in the workshop. The other two propellers
were used to automate the four methods and validate them against model test results.
The CFD analyses were performed with the open source CFD toolbox OpenFOAM. Steady
Reynolds-Averaged Navier-Stokes (RANS) simulations with <i>k</i> − ωSST turbulence model
and wall functions in combination with Multiple Reference Frames (MRF) were used for the
CFD simulations. The grids and automatic CFD pre-processing were performed with the
commercial meshing software ANSA. The boundary element method predictions and grid
generation were performed in the CRS developed tool PROCAL. The lifting line method
predictions were performed in an Excel workbook with macros. The Wageningen Series
predictions came directly from the Wageningen polynomials. The three latter methods were
automated using visual basic and Excel.
One important conclusion is that CFD gives the most accurate predictions, but requires many
CPU-hours. When results are needed quickly, the boundary element method is useful and
accurate enough. The lifting line method generates less accurate results than the other
methods. The Wageningen Series is useful to give an indication of the predicted results
validity. The automated codes save hours of work and results in consequent setups.
PB Institutionen för sjöfart och marin teknik, Fartygs framdrivning och miljöpåverkan, Chalmers tekniska högskola,
T3 Report. X - Department of Shipping and Marine Technology, Chalmers University of Technology, Göteborg, Sweden, no: 264
LA eng
LK http://publications.lib.chalmers.se/records/fulltext/146813.pdf
OL 30