flow around a train body

Flow Around Vehicles Under the Influence of Side Winds



PhD student: Hassan Hemida
hemida@chalmers.se
Supervisor: Sinisa Krajnovic
sinisa@chalmers.se
Co-supervisor, examiner: Lars Davidson
lada@chalmers.se
Cooperation: Scania, Bombardier Transportation, ANSYS Fluent Sweden
Sponsors: Vinnova, Scania, Bombardier Transportation, ANSYS Fluent
Publications: [1-12]
Start of project: August 2003


BACKGROUND
Many traffic accidents are caused by side winds. These accidents can be collisions caused by substantial vehicle course deviations, the overturning of the vehicles or derailment accidents. It is well known that the shape of the vehicle determines the influence of the side winds on the vehicle stability. Thus the vehicle's side wind resistance can be improved by the adjustment of its design. This task requires thorough understanding of the flow around vehicles under the influence of side winds. Previous experimental studies have concentrated mainly on the vehicle's response to the side winds and not much on the understanding the flow mechanisms.
 
PROJECT
This project aims to study the influence of the side winds on the road and rail vehicles such as trains, trucks and buses. We are using time-dependent numerical technique (large eddy simulations) to accurately predict the flow and to study its development in time. Two generic geometries will be studied during the project. First the geometry of a simplified train body will be used following by a simplified truck geometry. Results of numerical simulations will be compared with the existing experimental data and with observations of the flows around real trains and trucks. The project will establish accurate picture of the flow around vehicles and provide explanations for the flow mechanisms that are influencing vehicles. This research will hopefully help the engineers and designers to improve the resistance of the vehicles to side winds.
 

 

 
REFERENCES
  1. H. Hemida, S. Krajnovic and L. Davidson, "Large-Eddy Simulations of the Flow Around a Simplified High Speed Train Under the Influence of a Cross-Wind", 17th AIAA Computational Fluid Dynamics Conference, Toronto, Ontario, Canada 6-9 June, 2005.
    View PDF file
     
  2. S. Krajnovic, H. Hemida and B. Diedrichs
    "Time-Dependent Simulations for the Directional Stability of High Speed Trains Under the Influence of Cross Winds or Cruising Inside Tunnels", Fluid Dynamics Applications in Ground Transportation "Simulation, a primary development tool in the automotive industry", Lyon, France, 26-27 October 2005.
    View PDF file
     
  3. H. Hemida
    HEMIDA, H.
    "Large-Eddy Simulation of the Flow around Simplified High-Speed Trains under Side Wind Conditions", thesis of Lic. of Engng, Division of Fluid Dynamics, Dept. of Applied Mechanics, Chalmers University of Technology, Göteborg, Sweden, 2006.
    View PDF file of thesis
     
  4. H. Hemida and S. Krajnovic
    "Exploring the Flow Around a Generic High-Speed Train Under the Influence of Side Winds Using LES", Fourth International Symposium on Computational Wind Engineering, July 16-19 Yokohama, Japan, 2006.
    View PDF file
     
  5. H. Hemida and S. Krajnovic
    "Numerical Study of the Unsteady Flow Structures Around Train-Shaped Body Subjected to Side Winds", ECCOMAS CFD 2006 (to be presented)", September 5-8, 2006, Egmond aan Zee, The Netherlands, 2006.
    View PDF file
     
  6. H. Hemida and S. Krajnovic
    "LES Study of the Impact of the Wake Structures on the Aerodynamics of a Simplified ICE2 Train Subjected to a Side Wind", Fourth International Conference on Computational Fluid Dynamics ICCFD4, Ghent, Belgium, 10-14 July, 2006.
    View PDF file
     
  7. H. Hemida and S. Krajnovic
    "LES Study of the Influence of the Vortex Generators on Cooling of Surface-Mounted Cubes", Therma Issues in Emerging TEchnologies, ThETA 1, Cario, Egypt, 2007.
    View PDF file
     
  8. H. Hemida and S. Krajnovic
    "DES of the Flow Around a Realistic Bus Model Subjected to a Side Wind with 30o Yaw Angle", The fifth IASME/WSEAS International Conference on Fluid Mechanics and Aerodynamics, Athens, Greece, 2007.
    View PDF file
     
  9. Spehr, F.
    "Numerical Study of Passive Flow Control on the Cooling of a Matrix of Surface-Mounted Cubes using LES", MSc Thesis, Division of Fluid Dynamics, Dept. of Applied Mechanics, Chalmers University of Technology, Göteborg, Sweden, 2007.
    View PDF file
     
  10. H. Hemida and S. Krajnovic
    "Parallel CFD Computations of Cross-Wind Stability on an ICE2 Train", PARA'06: Workshop on State-of-the-art in Scientific and Parallel Computing, Umeå, Sweden,2006.
    View PDF file
     


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