THE PROJECT
Large Eddy Simulations will be used to predict flow
around cars. With LES we expect to be able to predict a number of physical
phenomena,
such as large-scale structured, unsteadiness etc.
LES of the flow around a car will give a deeper understanding of the flow
and will
help Volvo to optimize the flow around vehicles and thus to design cars and trucks in
an aerodynamically
better way.
Initially we will work on LES around bluff bodies. The most
well-documented test case
is a surface-mounted cube where flow visualizations and detailed
LDA measurements have been carried out. This
flow has also been studied with LES in two
workshops, one in Rottach-Egern, Germany
and one in Delft, The Netherlands. This flow will be
computed both with
the computer code CALC-LES used at
Chalmers and
with the CFX4 code used at Volvo IT. The results obtained with
the two methods will be evaluated
and one of the codes will be used for the car simulations (see below).
We plan to use two type of subgrid models: the simple Smagorinsky
model and a new one-equation model which has been developed at the department.
Both type of models are applicable to
general three-dimensional flow.
A 64-processor Origin 2000 Silicon Graphics machine will be used.
The code has been parallelized by
Zacharov [1]. As an example a speed-up of 3.4 (6.2) on 4 (8) processors
has been obtained inother projects.
REFERENCES
- click to view postscript file
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I. Zacharov, private communication, European Supercomputer Team, Silicon
Graphics Inc., Switzerland, 1997.
-
S. Krajnovic
Large-Eddy Simulation of the Flow Around a
Surface-Mounted Single Cube in a Channel, Master thesis, Rept. 98/7,
Thermo and Fluid Dynamics,
Chalmers University of Technology, Gothenburg, 1998.
View PDF file
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Krajnovic, S., Müller, D., Davidson, L.
"Comparison of Two One-Equation Subgrid Models
in Recirculating Flows", Direct and Large-Eddy Simulation III, pp. 63-74, Eds: P.V. Voke, N.D. Sandham & L. Kleiser
View PDF file
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Krajnovic, S., Davidson, L.
Large-Eddy Simulation of the Flow Around a Surface-Mounted Cube Using a Dynamic
One-Equation Subgrid Model",
The First International Symp. on
Turbulence and Shear Flow Phenomena, Santa Barbara, Sept. 12-15, 1999.
pp. 741-746, Eds: S. Banerjee & J.K. Eaton, begell house, inc., New York, Wallingford U.K., 1999.
View PDF file
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Krajnovic, S., Davidson, L.
"Flow Around a Three-Dimensional Bluff Body",
9th International Symposium on Flow Visualisation, Heriot-Watt University, Edinburgh,
G.M. Carlomagno and I. Grant (Eds.), 2000.
View PDF file
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S. Krajnovic and L. Davidson
"Large Eddy Simulation of the Flow Around a Three-Dimensional
Bluff Body", AIAA paper 2001--0432, Reno, NV, 2001.
View PDF file
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S. Krajnovic and L. Davidson
"Large-Eddy Simulation of the Flow
Around a Ground Vehicle Body"
"SAE Paper 2001-01-0702, Detroit, 2001.
View PDF file
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S. Krajnovic and L. Davidson
"Large Eddy Simulations of the Flow Around A Simplified Bus",
3rd AFOSR International Conference on DNS and LES,
Arlington, Texas, 2001.
View PDF file
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S. Krajnovic and L. Davidson
"A Mixed One-Equation Subgrid Model for Large-Eddy Simulation",
International Journal of Heat and Fluid Flow,
Vol. 23, No. 4, pp. 413-425,
2002.
-
S. Krajnovic and L. Davidson
"Large Eddy Simulation of the Flow Around a Bluff Body",
AIAA Journal, Vol. 40, No. 5, pp. 927--936, 2002.
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S. Krajnovic and L. Davidson
"A test case for large-eddy simulation in vehicle aerodynamics",
"Engineering Turbulence Modelling and Experiments 5",
pp. 647--656, W. Rodi and N. Fueyo (Eds.), Elsevier, 2002.
View PDF file
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S. Krajnovic and L. Davidson
"Development of Large Eddy Simulation for Vehicle Aerodynamics",
IMECE/ASME HTD-2 TOC, New Orleans, Louisiana, 2002.
View PDF file
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S. Krajnovic and L. Davidson
Numerical study of the flow around the bus-shaped body,
ASME J. Fluid Engng., Vol. 125, pp. 500-509, 2003.
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S. Krajnovic and L. Davidson
"Exploring the Flow Around a Simplified Bus with Large Eddy Simulation and Topological Tools",
The Aerodynamics of Heavy Vehicles: Trucks, Buses and Trains,
Monterey-Pacific Grove, California, USA, 2002
View PDF file
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