Yavaş Değişen Kritik-Altı Açık Kanal Akımının k-ɛ Türbülans Kapatma Modelleri ile Sayısal Hesabı

Yıl 2014, Cilt: 29 Sayı: 1, 145 - 156, 25.07.2016

M. Ali İspir M. Salih Kırkgöz Veysel Gümüş

https://doi.org/10.21605/cukurovaummfd.242859

Cited By: 2

Öz

Yavaş değişen kritik-altı açık kanal akımının (M1 profili) hız alanı, Lazer Doppler Anemometresi (LDA) ile ölçülmüş ve aynı deney koşullarındaki akımlar için, temel denklemler, sonlu hacimler yöntemine dayalı ANSYS-Fluent paket programı ile çözülmüştür. Sayısal hesaplamalarda, Standard k-, Renormalization-group k-ɛ ve Realizable k-ε türbülans kapatma modelleri kullanılmış, su yüzü profili VOF yöntemi ile hesaplanmıştır. Sayısal modellerden elde edilen akım hızları deneysel ölçümlerle karşılaştırılmıştır. Farklı türbülans modellerinin deneysel olarak doğrulanması amacıyla yapılan karşılaştırmalarda, Realizable k-ε türbülans modelinin, hız alanının hesaplanmasında, kullanılan üç model arasında en başarılı olduğu görülmüştür

Anahtar Kelimeler

Açık kanal akımı, Hız profili, Sayısal hesaplama, VOF, Türbülans kapatma modelleri

Numerical Analysis of Gradually Varied Subcritical Open Channel Flow Using k-ɛ Turbulence Closure Models

Öz

The velocity field of gradually varied subcritical open channel flow (M1 profile) is measured using Laser Doppler Anemometry (LDA). Basic equations of the problem are solved by ANSYS-Fluent program package, using finite volume method, for the flow case having the same experimental conditions. In the numerical simulations, Standard k-ɛ, Renormalization-group k-ɛ and Realizable k-ε turbulence closure models are used, and the flow profile is computed using VOF method. Computational results for velocities are compared with measured data. Experimental validations of the turbulence models show that, Realizable k-ε turbulence model, among the three, is in general the most successful one in predicting the velocity field of the present flow case

Anahtar Kelimeler

Open channel flow, Velocity profile, Numerical analysis, VOF, Turbulence closure models

Kaynakça

• 1. Aydın, M.C. 2012. CFD simulation of freesurface flow over triangular labyrinth side weir. Advances in Engineering Software. 45(1): 159- 166.
• 2. Haun, S., Olsen, N.R.B. ve Feurich, R. 2011. Numerical Modeling of Flow over Trapezoidal Broad-Crested Weir. Engineering Applications of Computational Fluid Mechanics. 5(3): 397- 405.
• 3. Kırkgöz, M.S., Aköz, M.S. ve Öner, A.A. 2008. Experimental and Theoretical Analyses of Two-Dimensional Flows Upstream of Broad-Crested Weirs. Canadian Journal of Civil Engineering. 35(9): 975-986.
• 4. Öner, A.A., Aköz, M.S., Kırkgoz, M.S. ve Gümüş, V. 2012. Experimental Validation of Volume of Fluid Method for a Sluice Gate Flow. Advances in Mechanical Engineering
• 5-Gümüş, V., Aköz, M.S. ve Kırkgöz, M.S. 2013. Experimental and Numerical Modeling of Submerged Hydraulic Jump Downstream of a Sluice Gate. TEKNIK DERGI. 24(2): 6379- 6397.
• 6. Kırkgoz, M.S., Aköz, M.S. ve Öner, A.A. 2008. Experimental and Theoretical Analyses of Two-Dimensional Flows Upstream of Broad-Crested Weirs. Canadian Journal of Civil Engineering. 35(9): 975-986.
• 7. Kırkgöz, M.S., Aköz, M.S. ve Öner, A.A. 2009. Numerical Modeling of Flow Over a Chute Spillway. Journal of Hydraulic Research. 47(6): 790-797.
• 8. Launder, B.E. ve Spalding, D.B. 1972. Lectures in Mathematical Models of Turbulence. New York: Academic Press.
• 9. Yakhot, V., Orszag, S.A., Thangam, S., Gatski, T.B. ve Speziale, C.G. 1992. Development of Turbulence Models for Shear Flows by a Double Expansion Technique. Physics of Fluids a-Fluid Dynamics. 4(7): 1510-1520.
• 10. Shih, T.-H., Liou, W.W., Shabbir, A., Yang, Z. ve Zhu, J. 1995. A new k-ϵ Eddy Viscosity Model For High Reynolds Number Turbulent Flows. Computers & Fluids. 24(3): 227-238.
• 11. Hirt, C.W. ve Nichols, B.D. 1981. Volume of Fluid (VOF) Method for the Dynamics of Free Boundaries. Journal of Computational Physics. 39(1): 201-225.
• 12. ANSYS. 2012. FLUENT Theory Guide. USA: ANSYS Inc.
• 13.Chen, H.C. ve Patel, V.C. 1988. Near-Wall Turbulence Models for Complex Flows Including Separation. Aiaa Journal. 26(6): 641- 648.
• 14.Roache, P.J. 1998. Verification of Codes and Calculations. Aiaa Journal. 36(5): 696-702.
• 15.Celik, I.B., Ghia, U., Roache, P.J. ve Freitas, C.J. 2008. Procedure for Estimation and Reporting of Uncertainty Due to Discretization In CFD Applications. Journal of Fluids Engineering-Transactions of the Asme. 130(7).