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Bir ters-basamak üzerindeki engellerin etrafındaki akışın sayısal olarak incelenmesi

Year 2021, Volume: 36 Issue: 2, 1145 - 1158, 05.03.2021

Seyfettin Bayraktar

https://doi.org/10.17341/gazimmfd.646073
Cited By: 1

Abstract

Bu çalışmada, bir ters-basamak üzerine konumlandırılmış kare, daire ve eşkenar üçgen kesitli prizmatik engellerin akım alanı üzerindeki etkileri sayısal olarak incelenmiştir. Türbülanslı, üç-boyutlu, daimi ve sıkıştırılamaz olarak kabul edilen akış, modifiye k-omega türbülans modeli kullanılarak çözülmüştür. Elde edilen sonuçlar, boyutsuz sürtünme ve boyutsuz basınç katsayıları ile boyutsuz ayrılmış akış bölgesi cinsinden sunulmuşlardır. Çalışmada engellerin geometrik şekillerinin dışında, yüksekliklerinin (h) ilgili değişkenler üzerindeki etkileri basamak yüksekliği (H) ile boyutsuzlaştırılarak H/h=0,125; 0.25; 0,5 ve 1 için sunulmuştur. Üzerinde engel bulunmayan ters-basamak için elde edilen sayısal sonuçlar, Driver and Seegmiller, 1985`in deneysel verileri ile karşılaştırılarak sayısal modelin doğruluğu gösterilmiştir. Üzerinde engel olmayan ters-basamak üzerindeki akış göz önüne alındığında, sadece engellerin varlıklarının değil, aynı zamanda kesit şekillerinin de sürtünme katsayısı, basınç katsayısı ve boyutsuz ayrılmış akış bölgesi uzunluğu üzerinde etkilerinin olduğu görülmüştür. Ters-basamak üzerine konulmuş engellerin kesit geometrisi fark etmeksizin herhangi bir engelin varlığının, ayrılmış akış bölgesi uzunluğunu artırdığı, ancak en uzun bölgeye, eşkenar üçgen kesitli prizma kullanıldığında ulaşıldığı saptanmıştır. Engel yüksekliğinin ayrılmış akış bölgesi üzerindeki etkisinin H/h=0,25 ten sonra oldukça düşük olduğu belirlenmiştir.

Keywords

Ters-basamak ayrılma türbülans hesaplamalı akışkanlar dinamiği

References

  • 1. Armaly, B.F., Durst, F., Pereira, J.C.F., Schönung, B. Experimental and theoretical investigation of backward-facing step flow, J Fluid Mech 127: 473-496, 1983.
  • 2. Nie, J.H., Armaly, B.F., Three-dimensional convective flow adjacent to backward-facing step-effects of step height, Int J Heat Mass Tran 45: 2431-2438, 2002.
  • 3. Xie, W.A, Xi, G.N., Fluid flow and heat transfer characteristics of separation and reattachment flow over a backward-facing step, Int J Refrig 74: 177-189, 2017.
  • 4. Xie,W.A., Xi, G.N., Geometry effect o flow fluctuation and heat transfer in unsteady forced convection over backward and forward facing steps, Energy, 132, 49-56, 2017.
  • 5. Kondoh, T., Nagano, Y, Tsuji, T., Computational study of laminar heat transfer downstream of a backward-facing step, Int J Heat Mass Tran, 36: 577-591, 2017.
  • 6. Xu, J.H., Zou, S., Inaoka, K., Xi, G.N., Effect of Reynolds number on flow and heat transfer in incompressible forced convection over a 3D backward-facing step, International Journal of Refrigeration, 79, 164-175, 2017.
  • 7. Iwai, H., Nakabe, K., Suzuki, K., Flow and heat transfer characteristics of backward-facing step laminar flow in a rectangular duct, Int J Heat Mass Tran, 43: 457-471, 2000.
  • 8. Nie, J.H., Armaly, B.F., Reverse flow regions in three-dimensional backward-facing step flow, Int J Heat Mass Tran, 4:, 4713-4720, 2004.
  • 9. Mushyam, A., Bergada, J.M., Nayeri, C.N., A numerical investigation of laminar flow over a backward facing inclined step, Meccanica, 51, 1739-1762, 2016.
  • 10. Chen, Y.T., Nie, J.H., Armaly, B.F., Hsieh, H.T., Turbulent separated convection flow adjacent to backward-facing step-effects of step height, Int J Heat Mass Tran, 49: 3670-3680, 2006.
  • 11. Essel, E.E., Tachie, M.F., Roughness effects on turbulent flow downstream of a backward facing step, Flow Turbulence Combut, 94, 125-153, 2015.
  • 12. Bayraktar, S., Numerical solution of three-dimensional flow over angled backward-facing step with raised upper wall, J Appl Fluid Mech, 7: 155-167, 2014.
  • 13. Chiang, T.P., Sheu, T.W.H., Fang, C.C., Numerical investigation of vortical evolution in a backward-facing step expansion flow, Appl Math Model, 23: 915-932, 1999.
  • 14. Davidson, L., Two-equation hybrid RANS-LES models: A novel way to treat k and  at inlets and at embedded iterfaces, Journal of Turbulence, 18(4), 291-315, 2017.
  • 15. Avancha, R.V.R., Pletcher, R.H., Large eddy simulation of the turbulent flow past a backward-facing step with heat transfer and property variations, Int J Heat Fluid Fl, 23; 601-614, 2002.
  • 16. Rouizi, Y., Favennec, Y., Ventura, J., Petit, D., Numerical model reduction of 2d steady incompressible laminar flows: application on the flow over a backward-facing step, J Comput Phys, 228: 2239-2255, 2009.
  • 17. Erturk, E., Numerical solutions of 2-D steady incompressible flow over a backward-facing step, part i: high Reynolds number solutions, Comput Fluids, 37: 633-655, 2008.
  • 18. Kim, J.Y., Ghajar, A.J., Tang, C., Foutch, G.L., Comparison of near-wall treatment methods for high Reynolds number backward-facing step flow, Int J Comput Fluid D, 19: 493-500, 2005.
  • 19. Speziale, C.G., Ngo, T., Numerical solution of turbulent flow past a backward facing step using a nonlinear k-ε model, Int J Eng Sci, 26: 1099-1112, 1988.
  • 20. Valencia, A., Hinojosa, L., Numerical solutions of pulsating flow and heat transfer characteristics in a channel with a backward-facing step, Heat Mass Transfer, 32: 143-148, 1997.
  • 21. Huang, R., Luo, X., Ji, B., Ji, Q., Turbulent flows over a backward-facing step simulated using a modified partially averaged Navier-Stokes model, J Fluid Eng139, 044501-1/044501-7, 2017.
  • 22. Girimaji, S.S., Abdol-Hamid, K.S., Partially-averaged Navier-Stokes model for turbulence: implementation and validation, 43rd AIAA Aerospace Sciences Meeting and Exhibit, Jan. 10-13, Reno, Nevada, USA, 2005.
  • 23. Huang, R., Luo, X., Ji, B., Ji, Q., Turbulent flows over a backward facing step simulated using a modified partially averaged Navier-Stokes model` J Fluid Eng, 139.4, 044501, 2017.
  • 24. Wilcox, D.C., Formulation of k- turbulence model revisited, AIAA Journal, 46: 2823-2838, 2008.
  • 25. Menter, F.R., Improved two equation k- turbulence models for aerodynamic flows, NASA Technical Memorandum 103975, 1992.
  • 26. Shih, T.H., Zhu, J., Lumley, J.L., A realizable Reynolds stress algebraic equation model, NASA Technical Memorandum 105993, 1993.
  • 27. Driver, D.M., Seegmiller, H.L., Features of a reattaching turbulent shear layer in divergent channel flow, AIAA Journal 23:163-171, 1985.
  • 28. P.J. Celik, I.B., Ghia, U., Roache, Procedure for estimation and reporting of uncertainity due to discretization in (CFD) applications, J. Fluids, 130, 2008.
  • 29. Versteeg, H.K., Malalasekera, W., An introduction to computational fluid dynamics, the finite volume method, Pearson Education Ltd, Harlow, 2007.
  • 30. Rumsey, C.L., Compressibility considerations for k- turbulence models in hypersonic boundary-layer applications, J Spacecraft Rockets, 47.1: 11-20, 2010.
  • 31. Wilcox, D.W., Turbulence modeling for CFD, DCW Industries, La Canada, Kanada, 1994.
  • 32. Naphon, P., Suwagari, J., Effect of curvature ratios on the heat transfer and flow developments in the horizontal spirally coiled tubes, Int J Heat Mass Tran, 50: 444-451, 2007

Year 2021, Volume: 36 Issue: 2, 1145 - 1158, 05.03.2021

Seyfettin Bayraktar

https://doi.org/10.17341/gazimmfd.646073
Cited By: 1

Abstract

In the present study, the effects of the square, circular and equilateral triangular cross-sectional obstacles placed on a backward-facing step on the flow-field were investigated numerically. Assumed to be fully turbulent, three-dimensional, steady and incompressible flow was solved by modified k-omega turbulence model. Obtained results were exhibited in terms of non-dimensional friction and non-dimensional pressure coefficients in addition to non-dimensional reattachment length. Apart from the geometric shapes of the obstacles, the influence of their heights (h) on the relevant parameters were presented for H/h=0.125, 0.25, 0.5 and 1 by dimensionalizing with the step height (H). Results obtained for the backward-facing step without any obstacles were compared with the experimental data of Driver and Seegmiller, 1985 to show the accuracy of the model. It was shown that in comparison with the step without the obstacles, not only the existence of the obstacles but their cross-sectional shapes also affect friction and pressure coefficients and the reattachment length. Regardless of the cross-sectional geometry of the obstacles, it was detected that the existence of the obstacles increases the length of the recirculation, however, the longest regions were obtained when an equilateral triangular cross-sectional one was used. It was revealed that the effect of the height of the obstacle on the detached flow region is quite low for H/h=0.25.

Keywords

Backward-facing step separation turbulence obstacle recirculation

References

  • 1. Armaly, B.F., Durst, F., Pereira, J.C.F., Schönung, B. Experimental and theoretical investigation of backward-facing step flow, J Fluid Mech 127: 473-496, 1983.
  • 2. Nie, J.H., Armaly, B.F., Three-dimensional convective flow adjacent to backward-facing step-effects of step height, Int J Heat Mass Tran 45: 2431-2438, 2002.
  • 3. Xie, W.A, Xi, G.N., Fluid flow and heat transfer characteristics of separation and reattachment flow over a backward-facing step, Int J Refrig 74: 177-189, 2017.
  • 4. Xie,W.A., Xi, G.N., Geometry effect o flow fluctuation and heat transfer in unsteady forced convection over backward and forward facing steps, Energy, 132, 49-56, 2017.
  • 5. Kondoh, T., Nagano, Y, Tsuji, T., Computational study of laminar heat transfer downstream of a backward-facing step, Int J Heat Mass Tran, 36: 577-591, 2017.
  • 6. Xu, J.H., Zou, S., Inaoka, K., Xi, G.N., Effect of Reynolds number on flow and heat transfer in incompressible forced convection over a 3D backward-facing step, International Journal of Refrigeration, 79, 164-175, 2017.
  • 7. Iwai, H., Nakabe, K., Suzuki, K., Flow and heat transfer characteristics of backward-facing step laminar flow in a rectangular duct, Int J Heat Mass Tran, 43: 457-471, 2000.
  • 8. Nie, J.H., Armaly, B.F., Reverse flow regions in three-dimensional backward-facing step flow, Int J Heat Mass Tran, 4:, 4713-4720, 2004.
  • 9. Mushyam, A., Bergada, J.M., Nayeri, C.N., A numerical investigation of laminar flow over a backward facing inclined step, Meccanica, 51, 1739-1762, 2016.
  • 10. Chen, Y.T., Nie, J.H., Armaly, B.F., Hsieh, H.T., Turbulent separated convection flow adjacent to backward-facing step-effects of step height, Int J Heat Mass Tran, 49: 3670-3680, 2006.
  • 11. Essel, E.E., Tachie, M.F., Roughness effects on turbulent flow downstream of a backward facing step, Flow Turbulence Combut, 94, 125-153, 2015.
  • 12. Bayraktar, S., Numerical solution of three-dimensional flow over angled backward-facing step with raised upper wall, J Appl Fluid Mech, 7: 155-167, 2014.
  • 13. Chiang, T.P., Sheu, T.W.H., Fang, C.C., Numerical investigation of vortical evolution in a backward-facing step expansion flow, Appl Math Model, 23: 915-932, 1999.
  • 14. Davidson, L., Two-equation hybrid RANS-LES models: A novel way to treat k and  at inlets and at embedded iterfaces, Journal of Turbulence, 18(4), 291-315, 2017.
  • 15. Avancha, R.V.R., Pletcher, R.H., Large eddy simulation of the turbulent flow past a backward-facing step with heat transfer and property variations, Int J Heat Fluid Fl, 23; 601-614, 2002.
  • 16. Rouizi, Y., Favennec, Y., Ventura, J., Petit, D., Numerical model reduction of 2d steady incompressible laminar flows: application on the flow over a backward-facing step, J Comput Phys, 228: 2239-2255, 2009.
  • 17. Erturk, E., Numerical solutions of 2-D steady incompressible flow over a backward-facing step, part i: high Reynolds number solutions, Comput Fluids, 37: 633-655, 2008.
  • 18. Kim, J.Y., Ghajar, A.J., Tang, C., Foutch, G.L., Comparison of near-wall treatment methods for high Reynolds number backward-facing step flow, Int J Comput Fluid D, 19: 493-500, 2005.
  • 19. Speziale, C.G., Ngo, T., Numerical solution of turbulent flow past a backward facing step using a nonlinear k-ε model, Int J Eng Sci, 26: 1099-1112, 1988.
  • 20. Valencia, A., Hinojosa, L., Numerical solutions of pulsating flow and heat transfer characteristics in a channel with a backward-facing step, Heat Mass Transfer, 32: 143-148, 1997.
  • 21. Huang, R., Luo, X., Ji, B., Ji, Q., Turbulent flows over a backward-facing step simulated using a modified partially averaged Navier-Stokes model, J Fluid Eng139, 044501-1/044501-7, 2017.
  • 22. Girimaji, S.S., Abdol-Hamid, K.S., Partially-averaged Navier-Stokes model for turbulence: implementation and validation, 43rd AIAA Aerospace Sciences Meeting and Exhibit, Jan. 10-13, Reno, Nevada, USA, 2005.
  • 23. Huang, R., Luo, X., Ji, B., Ji, Q., Turbulent flows over a backward facing step simulated using a modified partially averaged Navier-Stokes model` J Fluid Eng, 139.4, 044501, 2017.
  • 24. Wilcox, D.C., Formulation of k- turbulence model revisited, AIAA Journal, 46: 2823-2838, 2008.
  • 25. Menter, F.R., Improved two equation k- turbulence models for aerodynamic flows, NASA Technical Memorandum 103975, 1992.
  • 26. Shih, T.H., Zhu, J., Lumley, J.L., A realizable Reynolds stress algebraic equation model, NASA Technical Memorandum 105993, 1993.
  • 27. Driver, D.M., Seegmiller, H.L., Features of a reattaching turbulent shear layer in divergent channel flow, AIAA Journal 23:163-171, 1985.
  • 28. P.J. Celik, I.B., Ghia, U., Roache, Procedure for estimation and reporting of uncertainity due to discretization in (CFD) applications, J. Fluids, 130, 2008.
  • 29. Versteeg, H.K., Malalasekera, W., An introduction to computational fluid dynamics, the finite volume method, Pearson Education Ltd, Harlow, 2007.
  • 30. Rumsey, C.L., Compressibility considerations for k- turbulence models in hypersonic boundary-layer applications, J Spacecraft Rockets, 47.1: 11-20, 2010.
  • 31. Wilcox, D.W., Turbulence modeling for CFD, DCW Industries, La Canada, Kanada, 1994.
  • 32. Naphon, P., Suwagari, J., Effect of curvature ratios on the heat transfer and flow developments in the horizontal spirally coiled tubes, Int J Heat Mass Tran, 50: 444-451, 2007
There are 32 citations in total.

Details

Primary Language Turkish
Subjects Engineering
Journal Section Makaleler
Authors

Seyfettin Bayraktar 0000-0002-1554-353X

Publication Date March 5, 2021
Submission Date November 12, 2019
Acceptance Date January 1, 2021
Published in Issue Year 2021 Volume: 36 Issue: 2

Cite

APA Bayraktar, S. (2021). Bir ters-basamak üzerindeki engellerin etrafındaki akışın sayısal olarak incelenmesi. Gazi Üniversitesi Mühendislik Mimarlık Fakültesi Dergisi, 36(2), 1145-1158. https://doi.org/10.17341/gazimmfd.646073
AMA Bayraktar S. Bir ters-basamak üzerindeki engellerin etrafındaki akışın sayısal olarak incelenmesi. GUMMFD. March 2021;36(2):1145-1158. doi:10.17341/gazimmfd.646073
Chicago Bayraktar, Seyfettin. “Bir Ters-Basamak üzerindeki Engellerin etrafındaki akışın sayısal Olarak Incelenmesi”. Gazi Üniversitesi Mühendislik Mimarlık Fakültesi Dergisi 36, no. 2 (March 2021): 1145-58. https://doi.org/10.17341/gazimmfd.646073.
EndNote Bayraktar S (March 1, 2021) Bir ters-basamak üzerindeki engellerin etrafındaki akışın sayısal olarak incelenmesi. Gazi Üniversitesi Mühendislik Mimarlık Fakültesi Dergisi 36 2 1145–1158.
IEEE S. Bayraktar, “Bir ters-basamak üzerindeki engellerin etrafındaki akışın sayısal olarak incelenmesi”, GUMMFD, vol. 36, no. 2, pp. 1145–1158, 2021, doi: 10.17341/gazimmfd.646073.
ISNAD Bayraktar, Seyfettin. “Bir Ters-Basamak üzerindeki Engellerin etrafındaki akışın sayısal Olarak Incelenmesi”. Gazi Üniversitesi Mühendislik Mimarlık Fakültesi Dergisi 36/2 (March 2021), 1145-1158. https://doi.org/10.17341/gazimmfd.646073.
JAMA Bayraktar S. Bir ters-basamak üzerindeki engellerin etrafındaki akışın sayısal olarak incelenmesi. GUMMFD. 2021;36:1145–1158.
MLA Bayraktar, Seyfettin. “Bir Ters-Basamak üzerindeki Engellerin etrafındaki akışın sayısal Olarak Incelenmesi”. Gazi Üniversitesi Mühendislik Mimarlık Fakültesi Dergisi, vol. 36, no. 2, 2021, pp. 1145-58, doi:10.17341/gazimmfd.646073.
Vancouver Bayraktar S. Bir ters-basamak üzerindeki engellerin etrafındaki akışın sayısal olarak incelenmesi. GUMMFD. 2021;36(2):1145-58.

Cited By

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Journal of Physics: Conference Series
https://doi.org/10.1088/1742-6596/2752/1/012108