مقایسه مدل های آشفتگی در تخمین تنش برشی بستر پیرامون تکیه گاه پل در مقطع مرکب

نوع مقاله : مقاله پژوهشی

نویسندگان

1 استادیار، گروه علوم و مهندسی آب، دانشگاه بیرجند

2 دانشجوی کارشناسی ارشد، گروه علوم و مهندسی آب، دانشگاه بیرجند

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Comparison of Turbulence Models for Estimation of Bed Shear Stress Around Bridge Abutment in Compound Channel

نویسندگان [English]

  • Y Ramezani 1
  • R Babagoli 2
چکیده [English]

Bridge failures due to scour at bridge abutments clarify importance of flow field around them.
Scope of this study is the comparison between experimental results and numerical simulation of bed
shear stress around bridge abutment in a compound channel by Flow-3D model. In order to calculate
the experimental bed shear stress, flow velocity was measured by a 3D electromagnetic velocimeter
in different levels of flow depth of floodplain. For estimation of Reynolds stresses of u¢w¢ ,u¢v¢ and
v¢w¢ , in low flow depth of floodplain, extrapolations of these values to the bed were used.
Experimental results showed that maximum bed shear stress occurred at the upstream corner of the
abutment. After mesh generation, hydraulic simulation of flow with Flow-3D model was run in 5
turbulent models of Prandtl mixing-length model, one equation turbulent energy model, k-ɛ model,
renormalized group (RNG) model and large eddy simulation model. Comparison between models
showed that the results achieved by the RNG model had a better agreement with experimental
observations and the pattern of shear stress around the bridge abutment was well predicted by this
model. Bed shear stress at the upstream corner of the abutment was determined by experimental
results and RNG model giving 3.84 and 4.6 N/m2, respectively.

کلیدواژه‌ها [English]

  • Bed shear stress
  • Bridge abutment
  • Flow-3D model
  • Reynolds stresses
  • Turbulence model

مراجع

منابع مورداستفاده
رمضانی ی و قمشی م، 1393. مطالعه تنش برشی بستر پیرامون تکیه­گاه پل در حضور پوشش گیاهی صلب غیر مستغرق روی دشت سیلابی. مجله هیدرولیک، جلد 9، شماره 1، صفحه­های 45 تا 57.
Ahmed F and Rajaratnam N, 2000. Observations on flow around an abutment. Journal of Engineering Mechanics 125(1): 51-59.
Barbhuiya A K and Dey S, 2003. Vortex flow field in a scour hole around abutments. International Journal of Sediment Research 18(4): 310-325.
Barbhuiya A K and Dey S, 2004. Local scour at abutments: a review. Sadhana, Indian Academy of Sciences 29(139): 449-476.
Dey S and Barbhuiya A K, 2005a. Flow field at a vertical-wall abutment. Journal of Hydraulic Engineering ASCE 131(12): 1126-1135.
Dey S and Barbhuiya A K, 2005b. Turbulent flow field in a scour hole at a semicircular abutment. Canadian Journal of Civil Engineering 32(1): 213-232.
Dey S and Barbhuiya A K, 2006a. 3D flow field in a scour hole at a wing-wall abutment. Journal of Hydraulic Research 44(1): 33-50.
Dey S and Barbhuiya A K, 2006b. Velocity and turbulence in a scour hole at a vertical-wall abutment. Journal of Flow Measurement and Instrumentation 17(1): 13-21.
Duan J G, 2009. Mean flow and turbulence around a laboratory spur dike. Journal of Hydraulic Engineering ASCE 135(10): 803-811.
Anonymous, 2004. Enhanced abutment scour studies for compound channels. Publication No. FHWA-RD-99-156.
Kwan F, 1984. Study of abutment scour. Report No. 328, School of Engineering, University of Auckland, New Zealand.
Kwan F, 1988. Study of abutment scour. Report No. 451, School of Engineering, University of Auckland, New Zealand.
Melville B W, 1992. Local scour at bridge abutments. Journal of Hydraulic Engineering ASCE 118(4): 615-631.
Melville B W, 1995. Bridge abutment scour in compound channels. Journal of Hydraulic Engineering ASCE 121(12): 863-868.
Molinas A, Kheireldin K and Baosheng W, 1998. Shear stress around vertical wall abutments. Journal of Hydraulic Engineering ASCE 124(8): 822-830.
Teruzzi A, Ballio F and Armenio V, 2009. Turbulent Stresses at the Bottom Surface near an Abutment: Laboratory-Scale Numerical Experiment. Journal of Hydraulic Engineering ASCE 135(2): 106-117.
Ursic M C, 2011. Quantification of shear stress in a meandering native topographic channel using a physical hydraulic model. M.Sc. Thesis, Fort Collins, Colorado, USA.
دانش آب و خاک
دوره 26، شماره 2 بخش 2
شهریور 1395
صفحه 95-109

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