International Scientific Journal

Thermal Science - Online First

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Comparison of different CFD software performances in the case of an incompressible air flow through a straight conical diffuser

Numerical flow simulations have been carried out in order to analyze the possibilities of numerical prediction of a steady-state incompressible air flow through a conical diffuser named Azad diffuser. The spreading angle of this diffuser is 8º and it has cylindrical parts of the constant diameter in the inlet and outlet flow zones. Numerical analysis has been performed by the use of the standard k-e turbulence model. The simulations have been performed using the Ansys CFX and the OpenFOAM software for cases of 2-D and 3-D computational domains. In both cases a fully developed turbulent flow at the inlet section of diffuser is present. The numerical flow simulation in a 2-D computational domain has been performed under the assumption of an axisymmetric flow in the diffuser. Numerically obtained results have been compared with experimental data. Results obtained with these two softwares have also been mutually compared. At the end the results obtained by CFD for the cases of 2-D and 3-D computational domains have been mutually compared, and the advantages and disadvantages of performing numerical simulations under the assumption of an axisymmetric flow in the diffuser have been analyzed. [Projekat Ministartsva nauke Republike Srbije, br. TR 35046 i br. TR 33046]
PAPER REVISED: 2016-11-22
PAPER ACCEPTED: 2016-12-05
  1. Okwuobi P. A. C., Turbulence in a Conical Diffuser With Fully Developed Flow at Entry, Ph. D. thesis, Department of Mechanical Engineering, Winipeg, Manitoba, October 1972.
  2. Okwuobi P. A. C., Azad R. S., Turbulence in a Conical Diffuser With Fully Developed Flow at Entry, J. Fluid Mech., 57 (1973), 3, pp. 603-622
  3. Chien J. C., Numerical Analysis of Turbulent Separated Subsonic Diffuser Flow, USAF Research report AEDC-TR-76-15, Arnold Air Force Station, Tennessee, 1977.
  4. Armfield S. W., Fletcher C. A. J., Comparison of k- and Algebraic Reynolds Stress Models for Swirling Diffuser Flow, International Journal for Numerical Methods in Fluids, 9 (1989), pp. 987-1009.
  5. Kobayashi T., Morinishi Y., Numerical Prediction of Turbulent Flow in a Conical Diffuser Using Model, Acta Mechanica Sinica 2 (1992), 8, pp.117-126.
  6. Zhu J., Shih T.-H., Calculations of Diffuser Flows With an Anisotropic k- model, NASA Contractor Report 198418, Cleveland, Ohayo, November 1995.
  7. Prakash R., et al., CFD Analysis of Flow Through a Conical Exhaust Diffuser, International Journal of Research in Engineering and Technology, 3 (2014), 11, pp. 239-248.
  8. Bonous O., Studies of the ERCOFTAC Conical Diffuser with OpenFOAM, Research report 2008:05, Chalmers University of Technology, Göteborg, Sweden, 2008.
  9. Novković Đ., et al., Numerical Flow Simulation in a Conical Diffuser, Energy 2016, 27-th Conference of Energy, Zlatibor, Serbia, 2016, Vol. 2, pp. 234-240.
  10. Coelho J. G., et al., Experimental and Numerical Study of the Swirling Flow in Conical Diffusers, Journal of Engineering Science and Technology, 9 (2014), 5, pp. 657 - 669.
  11. Muntean S., et al., 3D Numerical Analysis of The Unsteady Turbulent Swirling Flow in a Conical Diffuser using FLUENT and OpenFOAM, 3rd IAHR International Meeting of the Workgroup on Cavitation and Dynamic Problems in Hydraulic Machinery and Systems, Brno, Czech Republic, 2009.
  12. Lee J., et al., Direct Numerical Simulations of Turbulent Flow in a Conical Diffuser, J. of Turbulence 13 (2012), 30, pp. 1-29.
  13. Launder B. E. and Spalding D. B., The numerical computation of turbulent flows, Computer Methods in Applied Mechanics and Engineering, 3 (1974), 2, pp. 269-289.
  14. McDonald A. C. and Fox R. W., Effect of Swirling Flow on Pressure Recovery in Conical Diffusers, AIAA Journal, 9 (1970), 10, pp. 2014-2018.