A Comparative Analysis of Turbulence Models Utilised for the Prediction of Turbulent Airflow through a Sudden Expansion

Abstract:

The turbulent airflow in a circular duct with sudden expansion was investigated utilizing three turbulence models. The turbulence models chosen are: the k-epsilon model, the shear stress transport model and the Reynolds-stress model. The performance of the models was investigated with respect to the flow parameter-recirculation length. The turbulent kinetic energy and velocity predictions were compared between the turbulence models and with experimental data, then interpreted on the basis of the recirculation length. From the results, the shear stress transport model predictions of recirculation length had the closest agreement with the experimental result compared to the other model. Likewise, the convergence rate for the shear stress transport model was reasonable compared to that of the Reynolds model which has the slowest convergence rate. In light of these findings, the shear stress transport model was discovered to be the most appropriate for the investigation of turbulent air flow in a circular duct with sudden expansion. Keywords: Turbulence, recirculation length, sudden expansion, Turbulence models.

• Periodical: International Journal of Engineering Research in Africa (Volume 16)
• Pages: 64-78
• DOI: https://doi.org/10.4028/www.scientific.net/JERA.16.64
• Online since: June 2015
• Authors: Karinate Valentine Okiy*
• Keywords: Recirculation Length, Sudden Expansion, Turbulence, Turbulence Models

References

[1] H.K. Versteeg and W. Malalasekera. 1995. An Introduction to Computational Fluid Dynamics. Essex. Longman Group Limited.

[2] K. Avila, D. Moxey, A. de Lozer, M. Avila, D. Barkey and B. Hof. 2011. The Onset of Turbulence in Pipe Flow. Science. 333(6039). pp.192-196.

DOI: 10.1126/science.1203223

[3] Wikipedia. 2011. Turbulence [online]. [Accessed 5 March 2011]. Available from: http: /wikipedia. org/wiki/turbulence.

[4] R. Vikram, M. Snehamoy and S. Dipankar. 2010. Analysis of the Turbulent Fluid flow in an axi-symmetric sudden expansion. International Journal of Engineering Science and Technology. 2(6). pp.1569-1574.

[5] S. Kangovi and R.H. Page. 1977. The Turbulent flow through a sudden enlargement at subsonic speeds. 6th Australasian Hydraulics and Fluid Mechanics Conference. Adelaide. pp.213-216.

[6] H. Tennekes and J.L. Lumley. 1972. A First Course in Turbulence. Cambridge: MIT Press.

[7] V.I. Terekhov and M.A. Pakhomov. 2011. Particle Dispersion and Turbulence modification in a dilute mist non-isothermal Turbulent flow downstream of a sudden pipe expansion. Journal of Physics. 318(9), pp.1-10.

DOI: 10.1088/1742-6596/318/9/092019

[8] N.A. Khalid. 2011. Flow and Heat Transfer characteristics downstream of a porous sudden expansion : A numerical study. Thermal Science. 15(2). pp.389-396.

DOI: 10.2298/tsci1102389a

[9] E.D. Koronaki, H.H. Liakos, M.A. Founti and N.C. Markatos. 2001. Numerical Study of Turbulent diesel flow in a pipe with sudden expansion. Applied Mathematical Modelling. 25. pp.319-333.

DOI: 10.1016/s0307-904x(00)00055-x