Advertisement

Prospects for Numerical Simulation of Bluff-Body Aerodynamics

  • C. W. Hirt
  • J. D. Ramshaw

Abstract

An improved understanding of the aerodynamics of bluff bodies such as road vehicles can lead to significant reductions in gasoline consumption and to increased safety and comfort. To achieve these goals improved theoretical and experimental techniques are urgently needed. This paper explores the potential of using numerical-simulation methods for predicting and interpreting aerodynamic phenomena affecting bluff bodies. As a basis for discussion, a prototype finite-difference method is described, and illustrated with sample calculations of air flow about simple bluff bodies. The limitations of this scheme are then discussed in detail, together with some suggestions for extensions that could be realized in the immediate future. The paper concludes with speculations on what could be achieved in the next five to ten years to produce a generally useful research tool for bluff-body aerodynamics.

Keywords

Reynolds Number Wall Shear Stress Eddy Viscosity Truncation Error Bluff Body 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Bradshaw, R. D. and Kramer, J. L. (1974), An Analytical Study of Reduced-Gravity Propellant Settling, National Aeronautics and Space Administration report NASA CR-134593.Google Scholar
  2. Brandt, A. (1972), Multi-Level Adaptive Technique (MLAT) for Fast Numerical Solution to Boundary Value Problems, Proc. Third International Conference on Numerical Methods in Fluid Mechanics, July 3–7, 1972, Paris, 18 pp. 82–89 Lecture Notes in Physics, Springer-Verlag, NY.CrossRefGoogle Scholar
  3. Buckingham, A. C. and Birnbaum, N. K. (1975), Three-Dimensional Compressible Flow Over a Rigid Structure: Explicit Finite-Difference and Integral Method Coupled at Slip Walls, Proc. 2nd AIAA Computational Fluid Dynamics Conference, Hartford, Conn., June 19–20 (1975).Google Scholar
  4. Chien, N., Feny, Y., Wang, H-J., Siao, T- T. (1951), Wind-Tunnel Studies of Pressure Distribution on Elementary Building Forms, Iowa Institute of Hydraulic Research, State University of Iowa, Iowa City, Iowa.Google Scholar
  5. Deardorff, J. W. (1971), On the Magnitude of the Subgrid Scale Eddy Coefficient, J. Comp. Phys. 7, pp. 120–133.MATHCrossRefGoogle Scholar
  6. Dienes, J. K., Hirt, C. W., and Stein, L. R. (1976), Computer Simulation of the Hydroelastic Response of a Pressurized Water Reactor to Sudden Depressurization, Proc. Fourth Water Reactor Safety Research Information Meeting, Washington, DC, September 27–30, 1976.Google Scholar
  7. Gosman, A. D. (1976), private communication.Google Scholar
  8. Hansen, A. C. and Cermak, J. E. (1975), Vortex-Containing Wakes in Surface Obstacles, Project THEMIS Technical Report No. 29, Fluid Dynamics and Diffusion Laboratory, College of Engineering, Colorado State University, Fort Collins, CO.Google Scholar
  9. Hanson, M. E. and Petschek, A. G. (1976), A Boundary Condition for Significantly Reducing Boundary Reflections with a Lagrangian Mesh, J. Comp. Phys. 21, pp. 333–339.CrossRefGoogle Scholar
  10. Harlow, F. H. and Welch, J. E. (1965) Numerical Calculations of Time-Dependent Viscous Incompressible Flow, Phys. Fluids 8, 2182;MATHCrossRefGoogle Scholar
  11. Welch, J. E., Harlow, F. H., Shannon, J. P., and Daly, B. J. (1966) The MAC Method: A Computing Technique for Solving Viscous, Incompressible, Transient Fluid-Flow Problems Involving Free Surfaces, Los Alamos Scientific Laboratory report LA-3425.Google Scholar
  12. Harlow, F. H. (1973) Editor, Turbulence Transport Modeling, Vol. XIV of AIAA Selected Reprint Series.Google Scholar
  13. Harlow, F. H. and Amsden, A. A. (1975), Numerical Calculation of Multiphase Fluid Flow, J. Comp. Phys. 17, 19.MATHCrossRefGoogle Scholar
  14. Hirt, C. W. (1968), Heuristic Stability Theory for Finite-Difference Equations, J. Comp. Phys. 2, pp. 339–355.MATHCrossRefGoogle Scholar
  15. Hirt, C W. and Cook, J. L. (1972), Calculating Three-Dimensional Flows around Structures and over Rough Terrain, J. Comp. Phys. 10, pp. 324–340.MATHCrossRefGoogle Scholar
  16. Hirt, C. W., Amsden, A. A., and Cook, J. L. (1974), An Arbitrary Lagrangian-Eulerian Computing Method for All Flow Speeds, J. Comp. Phys. 14, pp. 227–253;MATHCrossRefGoogle Scholar
  17. Amsden, A. A. and Hirt, C. W (1973), YAQUI: An Arbitrary Lagrangian-Eulerian Computer Program for Fluid Flows at All Speeds, Los Alamos Scientific Laboratory report LA-5100.Google Scholar
  18. Hirt, C. W. (1975), Numerical Hydrodynamics: Present and Potential, Proc. Workshop on Numerical Hydrodynamics, May 20–21, 1974, National Academy of Sciences, Washington, DC.Google Scholar
  19. Hirt, C. W, Nichols, B. D., and Romero, N. C (1975), SOLA - A Numerical Solution Algorithm for Transient Fluid Flows, Los Alamos Scientific Laboratory report LA-5852;Google Scholar
  20. Cloutman, L. D., Hirt, C. W., and Romero, N. C. (1976), SOLA-ICE: A Numerical Solution Algorithm for Transient Compressible Fluid Flows, Los Alamos Scientific Laboratory report LA 6236.Google Scholar
  21. Hirt, C. W. and Stein, L. R. (1976a), A Simple Scheme for Second Order Accuracy in Marker-and-Cell Codes, unpublished note.Google Scholar
  22. Hirt, C. W. and Stein, L. R. (1976b), Numerical Simulation of Wind Loads on Buildings, paper in preparation.Google Scholar
  23. Hotchkiss, R. S. and Hirt, C. W. (1972), Particulate Transport in Highly Distorted Three-Dimensional Flow Fields, Proc. Computer Simulation Conference, San Diego; also Los Alamos Scientific Laboratory report LA-DC-72–364.Google Scholar
  24. Landau, L. D. and Lifshitz, E. M. (1959), Fluid Mechanics, Pergamon Press, Addison-Wesley Publishing Co., Inc., Reading, Mass.Google Scholar
  25. Launder, B. E. and Spalding, D. B. (1972), Mathematical Models of Turbulence, Academic Press, New York, NY.Google Scholar
  26. McKay, M D., Conover, W. J., and Whiteman, D. E. (1976), Report on the Applications of Statistical Techniques to the Analysis of Computer Codes, Los Alamos Scientific Laboratory report LA-6479-MS.Google Scholar
  27. Morkovin, M V. (1972), An Approach to Flow Engineering via Functional Flow Modules, Proc. Themis Symposium on Vehicular Dynamics, Rock Island, Illinois, November 1971.Google Scholar
  28. Nichols, B. D. and Hirt, C. W. (1976), Numerical Calculation of Wave Forces on Structures, Proc. Fifteenth Conference on Coastal Engineering, July 11–17, 1976, Honolulu, Hawaii.Google Scholar
  29. Norton, J. L. and Ruppel, H. M. (1976), YAQUI User’s Manual for Fireball Calculations, Los Alamos Scientific Laboratory report LA-6261-M.Google Scholar
  30. Orlanski, I. (1976), A Simple Boundary Condition for Unbounded Hyperbolic Flows, J. Comp. Phys. 21, pp. 251–269.MATHCrossRefGoogle Scholar
  31. Orszag, S. A. (1973), Minicomputers vs Supercomputers: A Study in Cost Effectiveness for Large Numerical Simulation Programs, Flow Research Note No. 38, Flow Research, Inc., Kent, Washington.Google Scholar
  32. Orszag, S. A. (1976), Turbulence and Transition: A Progress Report, to be published.Google Scholar
  33. Pracht, W. E. (1975), Calculating Three-Dimensional Fluid Flows at All Speeds with an Eulerian-Lagrangian Computing Mesh, J. Comp. Phys. 17, pp. 132–159.MATHCrossRefGoogle Scholar
  34. Richtmyer, R. D. and Morton, K. W (1967), Difference Methods for Initial-Value Problems, Second Edition, Interscience Publishers, J. Wiley and Sons, New York, NY.Google Scholar
  35. Roache, P. J. (1972), Computational Fluid Dynamics, revised printing, Hermosa Publishers, Albuquerque, New Mexico.Google Scholar
  36. Schlichting, H. (1960), Boundary-Layer Theory, Sixth Edition, McGraw-Hill Book Co., New York, NY.Google Scholar
  37. Sklarew, R. C. (1970), A New Approach: The Grid Model of Urban Air Pollution, Proc. 63rd Annual Meeting of the Air Pollution Control Association, St. Louis, Missouri, June 14, 1970.Google Scholar
  38. Stein, L. R., Gentry, R. A., and Hirt, C. W (1976), Computational Simulation of Transient Blast Loading on Three-Dimensional Structures, to be published in Computer Methods in Applied Mechanics and Engineering.Google Scholar
  39. Trulio, J. G. (1964), Studies of Finite Difference Techniques for Continuum Mechanics, Air Force Weapons Laboratory report WL TDR-64–72, Kirtland Air Force Base, Albuquerque, New Mexico.Google Scholar
  40. Trulio, J. G. (1966), Theory and Structure of the AFTON Codes, Air Force Weapons Laboratory, Kirtland Air Force Base Report No. AFWL-TR-66–19.Google Scholar
  41. Trulio, J. G. (1969), Puff Rezone Development, Air Force Weapons Laboratory Report AFWL-TR-69–50, Kirtland Air Force Base, Albuquerque, New Mexico.Google Scholar
  42. Viecelli, J. A. (1969), A Method for Including Arbitrary External Boundaries in the MAC Incompressible Fluid Computing Technique, J. Comp. Phys. 4, pp. 543–551;MATHCrossRefGoogle Scholar
  43. Viecelli, J. A., A Computing Method for Incompressible Flows Bounded by Moving Walls, J. Comp. Phys. 8, pp. 119–143 (1971).MATHCrossRefGoogle Scholar
  44. von Neumann, J. and Richtmyer, R. D. (1950), A Method for the Numerical Calculation of Hydrodynamic Shocks, J. Appl. Phys. 21, pp. 232–237.MathSciNetMATHCrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1978

Authors and Affiliations

  • C. W. Hirt
    • 1
  • J. D. Ramshaw
    • 1
  1. 1.University of California Los Alamos Scientific LaboratoryLos AlamosUSA

Personalised recommendations