Kapalı Türbülanslı Çevrintili Akışların Modellemesi ve Sayısal Araştırılması

Bu orijinal araştırmada, dairesel kesitli ani genişlemeli borularda sürekli, sıkıştırılamayanve eksenel simetrik kapalı türbülanslı çevrintili akışların modellemesive sayısal araştırılması için üç farklı Reynolds sayılarında kapsamlı hesaplamalaryapılmıştır. Hibrit yöntemiyle sonlu hacim metodunu kullanarak, SIMPLE(Semi-Implicit Method for Pressure Linked Equations) algoritmasına dayanan birbilgisayar programı geliştirilmiştir. Standart k-ε türbülans modeli modellemesiyleberaber, süreklilik ve momentum korunum denklemlerinin sayısal çözümleri, iteratifbir sayısal çözüm tekniğini kullanarak sağlanmıştır. Katı cidarlar yakınındacidar fonksiyonları kullanılmıştır. Dairesel kesitli ani genişlemeli borularda çeşitlieksenel kesitlerde, eksenel hız, türbülans kinetik enerji, türbülans kinetik enerjikaybolma miktarı, efektif viskozite radyal profilleri, simetri ekseni boyunca eksenelhızın değişimi, geri akışın geometrik yeri, üst cidar boyunca cidar statik-basınçkatsayısının değişimi, üst cidar kayma gerilmesinin dağılımı ile üst cidar sürtünmekatsayısının değişimi için sayısal hesaplamalar sunulmuş ve çeşitli deneyselölçümlerle karşılaştırılarak incelenmiştir. Sayısal hesaplamaların sonuçları çeşitlideneysel ölçümlerle genel olarak iyi uyum göstermektedir.

Numerical Investigation and Modelling of Confined Turbulent Recirculating Flows

This original research work presents the results of an extensive study of numerical investigation and modelling of steady, incompressible, and axisymmetric confined turbulent recirculating flows in circular-sectioned sudden expansion pipes at three different Reynolds numbers. Employing the finite-volume method with a hybrid scheme, a computer program based on the SIMPLE (Semi-Implicit Method for Pressure Linked Equations) algorithm has been developed. Numerical solution of the conservation equations of mass and momentum, together with the standard k-ε turbulence model, are obtained using an iterative numerical solution technique. Near the solid boundaries, wall-functions are employed. Numerical predictions for radial profiles of axial velocity, turbulence kinetic energy, turbulence kinetic energy dissipation rate, effective viscosity, axial variation of centre-line velocity, locus of flow reversal, wall static-pressure coefficient, wall-shear stress and friction coefficient distributions along top wall of the axisymmetric sudden expansion pipe flow configuration are presented and compared with various experimental measurements. The results of numerical predictions show generally good agreement with various experimental data.

___

  • [1] Gould, R. D., Stevenson, W. H., and Thompson, H. D. (1990). Investigation of Turbulent Transport in an Axisymmetric Sudden Expansion, Aiaa Journal, 28, 276-283.
  • [2] Stevenson, W. H., Thompson, H. D., and Craig, R. R. (1984). Laser Velocimeter Measurements in Highly Turbulent Recirculating Flows. Asme J. Fluids Eng., 106, 173-180.
  • [3] Durrett, R. P., Stevenson, W. H., and Thompson, H. D. (1988). Radial and Axial Turbulent Flow Measurements With an LDV in an Axisymmetric Sudden Expansion Air Flow. Asme J. Fluids Eng., 110, 367-372.
  • [4] Chaturvedi, M. C. (1963). Flow Characteristics of Axisymmetric Expansions. J. Hydraulics Div., Proc., Asce, 89, Hy3, 61-92.
  • [5] Moon, L. F., and Rudi̇nger, G. (1977). Velocity Distribution in an Abruptly Expanding Circular Duct. Asme J. Fluids Eng., 99, 226-230.
  • [6] Favaloro, S. C., Nejad, A. S., and Ahmed, S. A. (1991). Experimental and Computational Investigation of Isothermal Swirling Flow in an Axisymmetric Dump Combustor. J. Propulsion, Aiaa J., 7 (3), 348-356.
  • [7] Nejad, A. S., Vanka, S. P., Avaloro, S. C., Samimy, M., and Langenfeld, C. (1989). Application of Laser Velocimetry for Characterization of Confined Swirling Flow. Asme J. Eng. for Gas Turbines and Power, 111, 36-45.
  • [8] Ahmed, S. A., and Nejad, A. S. (1992). Premixed, Turbulent Combustion of Axisymmetric Sudden Expansion Flows. Int. J. Heat and Fluid Flow, 13(1), 15-21.
  • [9] Ahmed, S. A., and Nejad, A. S. (1992). Velocity Measurements in a Research Combustor; Part 1: Isothermal Swirling Flow. Exp. Ther. Fluid Science, 5, 162-174.
  • [10] Ahmed, S. A. (1992). Ercoftac Database: Isothermal Dump Combustor With Swirl Experiments. Retrieved, From the World Wide Web. http://cfd.mace.manchester.ac.uk/ercoftac/ classif.html.
  • [11] Ahmed, S. A. (1998). Velocity Measurements and Turbulence Statistics of a Confined Isothermal Swirling Flow. Exp. Ther. Fluid Science, 17, 256-264.
  • [12] Nejad, A. S., and Ahmed, S. A. (1992). Flow Field Characteristics of An Axisymmetric Sudden Expansion Pipe Flow With Different Initial Swirl Distribution. Int. J. Heat and Fluid Flow, 13(4), 314-321.
  • [13] Ahmed, S. A., and Abi̇dogun, K. B. (1998). Measurements of Turbulence Statistics and Energy Budgets in a Model Combustor. Energy, 23(9), 741-752.
  • [14] Ahmed, S. A., and Abi̇dogun, K. B. (1997). An Experimental Investigation of Turbulence Statistics in an Axisymmetric Sudden Expansion. HTD-Vol. 346, National Heat Transfer Conference, Vol. 8, 101-110, Asme.
  • [15] Poole, R. J., and Escudi̇er, M. P. (2004). Turbulent Flow of Viscoelastic Liquids Through An Axisymmetric Sudden Expansion. J. Non-Newtonian Fluiech, 117, 25-46.
  • [16] Escudi̇er, M. P., and Smi̇th, S. (1999). Turbulent Flow of Newtonian and Shear-Thinning Liquids Through a Sudden Axisymmetric Expansion. Experiments in Fluids, 27, 427-434.
  • [17] Cole, D. R., and Glauser, M. N. (1998). Flying Hot-Wire Measurements in an Axisymmetric Sudden Expansion, Experimental Thermal and Fluid Science, 18, 150-167.
  • [18] Cole, D. R., and Glauser, M. N. (1998). Applications of Stochastic Estimation in the Axisymmetric Sudden Expansion, Physics of Fluids, 10(11), 2941-2949.
  • [19] Ti̇nney. E., Glauser, M. N., Eaton, E. L., and Taylor, J. A. (2006). Low Dimensional Azimuthal Characteristics of Suddenly Expanding Axisymmetric Flows, J. Fluid Mech, 567, 141-155.
  • [20] Devenport, W. J., and Sutton, E. P. (1993). An Experimental Study of Two Flows Through an Axisymmetric Sudden Expansion, Experiments In Fluids, 14, 423-432.
  • [21] Furui̇chi̇, N., Takeda, Y., and Kumada, M. (2003). Spatial Structure of the Flow Through an Axisymmetric Sudden Expansion, Experiments In Fluids, 34, 643-650.
  • [22] Mak, H., and Balaba, S. (2007). Near Field Characteristics of Swirling Flow Past a Sudden Expansion, Chemical Engineering Science, 62, 6726-6746.
  • [23] Lee, D. H., and Sung, H. J. (1994). Experimental Study of Turbulent Axisymmetric Cavity Flow, Experiments In Fluids, 17, 272-281.
  • [24] Karasu, T. (1980). Numerical Prediction of Incompressible Turbulent Swirling Flows In Circular-Sectioned Ducts and Annuli, Ph.d. Thesis, University of London, London, U.k.
  • [25] Karasu, T., Choudhury, P. R., and Gerstei̇n, M. (1988). Prediction of Some Turbuent Flows Using Upwind and Hybrid Discretisation Schemes and the Two-Equation Turbulence Model. Proc. 4th Miami International Symposium on Multi-Phase Transport and Particulate Phenomena, Miami Beach, Florida, U.S.A., 5, 105-124.
  • [26] Karasu, T. (1989). Prediction of Turbulent Flow With Heat Transfer in an Annulus With Rotating Inner Cylinder. Proc. 8Th Miami International Conference on Alternative Energy Sources, Miami Beach, Florida, U.s.a., Vol. 2, 361-385.
  • [27] Karasu, T. (1990). Numerical Prediction of Turbulent Swirling Flows In Circular-Sectioned Annuli, Proc. 5th Miami International Symposium on Multi-Phase Transport and Particulate Phenomena, Miami Beach, Florida, U.S.a., Vol. 1, 149-174.
  • [28] Karasu, T. (1990). Numerical Study of Turbulent Flow In Pipes, Proc. 6th Miami International Symposium on Heat and Mass Transfer, Miami, Florida, U.S.A.
  • [29] Karasu, T. (1997). Numerical Prediction of Turbulent Recirculating Flow Through Axisymmetric Sudden Expansions. 10Th International Conference on Numerical Methods in Laminar and Turbulent Flow, 21st –25th July 1997, Swansea, U.k., Proceedings Book, Vol. 10, 357-368.
  • [30] Karasu, T. (1993). Numerical Computation of Turbulent Flow In Pipes, Doğa-Tr. J. of Engineering and Environmental Sciences, 17, 29- 38.
  • [31] Karasu, T. (1988). Numerical Solution of Turbulent Flow With Heat Transfer in an Annulus With Rotating Inner Cylinder. Turkish Journal of Engineering and Environmental Sciences, 12(3), 250-272.
  • [32] Karasu, T. (1995). Numerical Prediction of Turbulent Flow In Circular Pipes. 9th International Conference on Numerical Methods In Laminar and Turbulent Flow, Atlanta, Georgia, U.S.A., Proceedings Book, Vol. 9, Part 2, 1329-1339.
  • [33] Karasu, T. (2017). Kapalı Türbülanslı Akışların Modellemesi ve Bilgisayarlı Simülasyonu. 20. Ulusal Mekanik Kongresi, 05-09 Eylül 2017, Uludağ Üniversitesi, Bursa, Türkiye. Bildiriler Kitabı, 1-12. Isbn 978-975561491-5.
  • [34] Karasu, T. (2018). Numerical Investigation and Modelling of Confined Turbulent Recirculating Flows, International Conference on Engineering Technologies (Icente’18), 26-28 October 2018, Selçuk University, Konya, Turkey, Proceedings Book, 419-433. E-Isbn: 978- 605-68537-3-9.
  • [35] Karasu, T. (2016). Computational Investigation of Turbulent Flow In Pipes. 3Rd International Conference on Advanced Technology and Sciences (Icat’16), 01-03 September 2016, Selçuk University, Konya, Turkey, Proceedings Book, 939-948.
  • [36] Karasu, T. (2017). Numerical Computation of Developing Turbulent Flow Between Two Parallel Plates. 21. Ulusal Isı Bilimi ve Tekniği Kongresi (Ulibtk’17), 13-16 Eylül 2017, Hitit Üniversitesi, Çorum, Türkiye, Bildiri Kitabı, 11-20.
  • [37] Karasu, T. (2017). Numerical Study of Turbulent Flow In Circular-Sectioned Pipes. 8th Atmospheric Sciences Symposium (Atmos’2017), 01-04 November 2017, Istanbul Technical University, Istanbul, Turkey, Proceedings Book, 663-674. Isbn: 978-975-561-490-8.
  • [38] Karasu, T. (2018). Numerical Investigation of Turbulent Recirculating Flow Through Plane Symmetric Sudden Expansions. Iv. Uluslararası Katılımlı Anadolu Enerji Sempozyumu (Aes’2018), 18-20 Nisan 2018, Trakya Üniversitesi, Edirne, Türkiye, Bildiri Kitabı, 2044- 2056.
  • [39] Karasu, T. (2017). Numerical Simulation of Internal Turbulent Flows, International Conference on Engineering Technologies (Icente’17), 07-09 December 2017, Selçuk University, Konya, Turkey, Proceedings Book, 679-688.
  • [40] Karasu, T. (2017). Computer Simulation and Modelling of Cofined Turbulent Flows. 21. Ulusal Isı Bilimi ve Tekniği Kongresi (Ulibtk’ 17), 13-16 Eylül 2017, Hitit Üniversitesi, Çorum, Türkiye, Bildiri Kitabı, 1-10.
  • [41] Karasu, T. (2017). Borularda Türbülanslı Akışların Sayısal Simülasyonu. Viii. Ulusal Hidrolik Pnömatik Kongresi, 22-25 Kasım 2017, İzmir. Bildiriler Kitabı, 69-83. MMO Yayın No: E/MMO/678. ISBN 978-605-01- 1088-3.
  • [42] Karasu, T. (2017). Paralel İki Plaka Arasında Gelişen Türbülanslı Akışın Sayısal Araştırılması. 20. Ulusal Mekanik Kongresi, 05-09 Eylül 2017, Uludağ Üniversitesi, Bursa, Türkiye. Bildiriler Kitabı, 13-24. ISBN 978-975561491- 5.
  • [43] Karasu, T. (2018). Computer Simulation of Turbulent Recirculating Flow Through Circular- Sectioned Sudden Expansion Pipes. 7th International Conference on Advanced Technologies (ICAT’18), April 28-May 1, 2018, Antalya, Turkey, Proceedings Book, 752-763. E-ISBN: 978-605-68537-1-5.
  • [44] Karasu, T. (2018). Numerical Investigation of Turbulent Recirculating Flow in Double-Sided Planar Sudden Expansions in Channels. 7th International Conference on Advanced Technologies (ICAT’18), April 28-May 1, 2018, Antalya, Turkey, Proceedings Book, 764-773. E-Isbn: 978-605-68537-1-5.
  • [45] Karasu, T. (2018). Computer Analysis and Modelling of Confined Turbulent Recirculating Flows, 4th International Conference on Advances In Mechanical Engineering (Icame’2018), 19-21 December 2018, Yıldız Technical University, Istanbul, Turkey, Proceedings Book, 363-382. Isbn 978-605-9546- 13-3.
  • [46] Launder, B. E., and Spaldi̇ng, D. B. (1974). The Numerical Computation of Turbulent Flows. Comp. Meth. Appl. Mech. Engng, 3, 269-289.
  • [47] Patankar, S. V. (1980). Numerical Heat Transfer and Fluid Flow, Hemisphee, Mcgraw-Hill, Washington, D.C., Chapters 5 and 6, 79-138.
  • [48] Patankar, S. V., and Spaldi̇ng, D. B. (1972). ACalculation Procedure for Heat, Mass and Momentum Transfer in Three-Dimensional Parabolic Flows, Int. J. Heat Mass Transfer, 15, 1787-1806.
  • [49] Spaldi̇ng, D. B. (1981). A General-Purpose Computer Program for Multi-Dimensional One-And-Two Phase Flow. Math, Comput. Simulation, XXIII, 267-276.