Modelling Boundary Shear Stress and Depth-Averaged Streamwise Velocity in the Breach

2021 ◽  
Vol 48 (4) ◽  
pp. 557-564
Author(s):  
Zhenzhen Liu ◽  
Tian Li ◽  
Yuxi Ding
2018 ◽  
Vol 92 ◽  
pp. 379-387 ◽  
Author(s):  
Lijuan Han ◽  
Yuhong Zeng ◽  
Li Chen ◽  
Ming Li

Water ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1001
Author(s):  
Juan Alfonso Figuérez ◽  
Álvaro Galán ◽  
Javier González

A 2D streamwise velocity model based on the Reynolds Averaged Navier–Stokes (RANS) is a useful approach to predict the boundary shear stress and the streamwise velocity in a free surface stream where secondary flows are not relevant. Boundary conditions treatment is a key aspect implementing these models. A low computational cost and fully predictive numerical model with a novel treatment of boundary conditions is presented. The main features of the modified model are the employment of a modified law of the wall valid for any roughness condition, the estimation of the boundary shear stress is done only focusing on the near-contour region, the use of a full-predictive physical based model for the eddy viscosity distribution and the incorporation of the free surface shear stress due to water–air interface. The validation of the proposed changes was performed with a substantial number of experimental cases available in the literature using different cross-section shapes (circular, rectangular, trapezoidal and compound section) and roughness condition with quite good agreement. Preliminary results suggest that the influence of the free surface boundary layer has a significant impact on the results for both the streamwise velocity and boundary shear stress in windy conditions. The proposed approach allows its considerations in practical applications.


2015 ◽  
Vol 4 ◽  
pp. 812-818 ◽  
Author(s):  
Sovan Sankalp ◽  
Kishanjit. K. Khatua ◽  
Arpan Pradhan

2016 ◽  
Vol 78 (9-4) ◽  
Author(s):  
Zulkiflee Ibrahim ◽  
Zulhilmi Ismail ◽  
Sobri Harun ◽  
Koji Shiono ◽  
Nazirah Mohd. Zuki ◽  
...  

Frequent floods around the globe including recent events in several states in Malaysia have damaged the residential properties, infrastructures and crops or even deaths. Clearing vegetations or trees on the floodplain has been pointed out as a contributing factor to the damages. Thus, the influence of floodplain vegetation on the river hydraulics during flooding must be better understood. The hydraulics of flood flows in non-erodible vegetated meandering channel was experimented in the laboratory where two-lined steel rods were installed along a riparian zone to simulate as trees. The stage-discharge relationship, flow resistance, depth-averaged velocity, streamwise vorticity and boundary shear stress patterns during shallow and deep flood inundations were studied. The findings showed that floodplain vegetation had increased the channel flow depth by 32% and its flow resistance. The velocity in vegetated zone was lowered and the shear stress reduced by 86.5% to 91% along the river meander. In addition, the trees also limit flow interaction between main channel and floodplain


2013 ◽  
Vol 20 (2) ◽  
pp. 161-168 ◽  
Author(s):  
M. Patnaik ◽  
K.C. Patra ◽  
K.K. Khatua ◽  
L. Mohanty

2005 ◽  
Vol 110 (F4) ◽  
pp. n/a-n/a ◽  
Author(s):  
E. R. Griffin ◽  
J. W. Kean ◽  
K. R. Vincent ◽  
J. D. Smith ◽  
J. M. Friedman

1968 ◽  
Vol 72 (696) ◽  
pp. 1059-1060 ◽  
Author(s):  
N. Rajaratnam ◽  
D. Muralidhar

Summary In this note it is suggested that the three-tube yaw probe be placed on the boundary and used as a Preston tube to measure the boundary shear stress when both its magnitude and direction are unknown. The calibration results necessary for this method are also presented herein.


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