Comparison of five different models in predicting the shear stress distribution in straight compound channels

Khozani, Zohreh Sheikh; Bonakdari, Hossein

doi:10.24200/sci.2016.2312

Cited by 9 publications

(11 citation statements)

References 19 publications

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“…The prediction of accurate values of shear stress due to designing more stable channels [13]. For prediction of shear stress distribution around wetted perimeter by using some analytical methods the mean wall and bed shear stresses also the percentage of shear force carried walls is needed [36][37][38]. Therefore, the more accurate results of these three parameters more accurate results of shear stress will be obtained.…”

Section: Discussionmentioning

confidence: 99%

Forecasting shear stress parameters in rectangular channels using new soft computing methods

Khozani¹,

Sheikhi²,

Mohtar³

et al. 2020

PLoS ONE

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Shear stress comprises basic information for predicting the average depth velocity and discharge in channels. With knowledge of the percentage of shear force carried by walls (% SF w ) it is possible to more accurately estimate shear stress values. The %SF w , non-dimension wall shear stress ( � t w t 0 ) and non-dimension bed shear stress ( � t b t 0 ) in smooth rectangular channels were predicted by a three methods, the Bayesian Regularized Neural Network (BRNN), the Radial Basis Function (RBF), and the Modified Structure-Radial Basis Function (MS-RBF). For this aim, eight data series of research experimental results in smooth rectangular channels were used. The results of the new method of MS-RBF were compared with those of a simple RBF and BRNN methods and the best model was selected for modeling each predicted parameters. The MS-RBF model with RMSE of 3.073, 0.0366 and 0.0354t 0 respectively, demonstrated better performance than those of the RBF and BRNN models. The results of MS-RBF model were compared with three other proposed equations by researchers for trapezoidal channels and rectangular ducts. The results showed that the MS-RBF model performance in estimating %SF w, � t w t 0 and � t b t 0 is superior than those of presented equations by researchers.

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Section: Discussionmentioning

confidence: 99%

Forecasting shear stress parameters in rectangular channels using new soft computing methods

Khozani¹,

Sheikhi²,

Mohtar³

et al. 2020

PLoS ONE

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“…where C s f = 1.0 for P b P w ≤ 4.374, unless C s f = 0.5857(P b /P w ) 0.28471 and in subcritical flow C 2 = 1.5; It is noted that Equations (26) to (30) were used in the studies of [13,25,26].…”

Section: Of 13mentioning

confidence: 99%

“…Zarrati et al [10] applied a simplified streamwise vorticity equation that includes secondary Reynolds stresses and proposed a semi-analytical model to predict shear stress distribution in simple and compound rectangular and trapezoidal channels. Although their proposed model performed well in predicting the shear stress distribution, the calculation of shear stress requires a number of equations, which is time-consuming [13]. The increasing use of new numerical methods based on a soft computing approach offers an alternative in the determination of shear stress distribution with more time effective.…”

Section: Introductionmentioning

confidence: 99%

“…The entropy concept is one of the analytical methods applied by Chiu [22] to forecast velocity and shear stress, where they employed the Shannon entropy. After the work of Chiu [22], many researchers utilized different entropy models for predicting different phenomena [13,[23][24][25][26][27][28][29]. Mirauda et al [30] applied the entropy concept to find a simple presentation of suspended sediment concentration.…”

Section: Introductionmentioning

confidence: 99%

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Investigation of New Tsallis-Based Equation to Predict Shear Stress Distribution in Circular and Trapezoidal Channels

Khozani

Mohtar

2019

Entropy

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In this study, the entropy concept is employed to estimate the shear stress distribution in a circular channel with flat bed and trapezoidal channel. Using the principle of maximum entropy, the shear stress distribution is derived by maximizing the Tsallis entropy by assuming averaged shear stress as a random variable. The derived shear stress equation can describe the variation of shear stress along the wetted perimeter of channel. The developed model of shear stress distribution is tested with some credible experimental data and is also compared with equations obtained by other researchers based on the Shannon entropy concept. The present model has shown good agreement with the observed data and performed better than the Shannon-based model in both cross-sections with better results of several computed quantitative criteria. The model precision in estimating shear stress in the trapezoidal channel with mean root mean square error (RMSE) of 0.0158 was higher than the circular channel with flat bed with RMSE of 0.0679.

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“…Sheikh Khozani and Bonakdari [18] used ve different methods to estimate the shear stress distribution in compound channels. The methods proposed by Yang and Lim (YLM) [19] [23] are compared with experimental data.…”

Section: Figure 1 Interaction Between Secondary Ow Cells Andmentioning

confidence: 99%

On the measurement of transverse shear stress on a rectangular open channel using optimal Preston tube

Lashkar-Ara

Fatahi

2018

Scientia Iranica

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The laboratory studies have been carried out in this research. After determining the sensitivity analysis of the Preston tube diameter in shear stress, four Preston tubes with external diameters of 3.2, 3.9, 4.7, and 6.3 mm were used. The aspect ratios of 2.86 to 13.95 were examined. For measuring the pressure di erence of the Preston tube, a 200 millibar di erential pressure transducer with 0.01 accuracy of the original scale was used. Laboratory results demonstrated that Preston tubes with a diameter of 3.9 mm presented the minimum di erence in the average value of the shear stress resulting from the Bechert and Patel calibration equations. Therefore, by using the Preston tube with an optimal diameter, transverse distribution of shear stress in channel beds and walls was determined. The outcome of this part of the study is two dimensionless relationships for determining the local shear stress both on the bed and wall. These relationships are a function of aspect ratio B=H and the bed relative coordinates b=B in cross-section and Z=H sidewall. The survey showed that the dimensionless bed shear stress distribution was considerably in uenced by the aspect ratio. The transverse distribution of wall shear stress was independent of the aspect ratio for B=H > 3.

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Comparison of five different models in predicting the shear stress distribution in straight compound channels

Cited by 9 publications

References 19 publications

Forecasting shear stress parameters in rectangular channels using new soft computing methods

Forecasting shear stress parameters in rectangular channels using new soft computing methods

Investigation of New Tsallis-Based Equation to Predict Shear Stress Distribution in Circular and Trapezoidal Channels

On the measurement of transverse shear stress on a rectangular open channel using optimal Preston tube

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