Comparing different methods of bed shear stress estimates in simple and complex flow fields

2004 ◽  
Vol 29 (11) ◽  
pp. 1403-1415 ◽  
Author(s):  
Pascale M. Biron ◽  
Colleen Robson ◽  
Michel F. Lapointe ◽  
Susan J. Gaskin
Keyword(s):  
Shear Stress ◽  
Flow Fields ◽  
Bed Shear Stress ◽  
Complex Flow

scholarly journals Comparison of Methods for Bed Shear Stress Estimation in Complex Flow Field of Bend

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2753
Author(s):  
Liyuan Zhang ◽  
Faxing Zhang ◽  
Ailing Cai ◽  
Zhaoming Song ◽  
Shilin Tong
Keyword(s):  
Shear Stress ◽  
Flow Field ◽  
Single Point ◽  
Three Dimensional ◽  
Bed Shear Stress ◽  
Complex Flow ◽  
Three Dimensional Flow ◽  
Stress Estimation ◽  
Log Law ◽  
Flow Field Measurement

Bed shear stress is closely related to sediment transport in rivers. Bed shear stress estimation is very difficult, especially for complex flow fields. In this study, complex flow field measurement experiments in a 60° bend with a groyne were performed. The feasibility and reliability of bed shear stress estimations using the log-law method in a complex flow field were analyzed and compared with those associated with the Reynolds, Turbulent Kinetic Energy (TKE), and TKE-w′ methods. The results show that the TKE, Reynolds, and log-law methods produced similar bed shear stress estimates, while the TKE-w′ method produced larger estimates than the other methods. The TKE-w′ method was found to be more suitable for bed shear stress estimation than the TKE method, but the value of its constant C2 needed to be re-estimated. In a complex, strong, three-dimensional flow field, the height of the measurement point (relative or absolute) should be re-estimated when a single point measurement is used to estimate the bed shear stress. The results of this study provide guidance for experimental measurement of bed shear stress in a complex flow field.

Efficiency prediction for storage chambers using computational fluid dynamics

1996 ◽  
Vol 33 (9) ◽  
pp. 163-170 ◽  
Author(s):  
Virginia R. Stovin ◽  
Adrian J. Saul
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Shear Stress ◽  
Particle Tracking ◽  
Critical Value ◽  
Complex Geometries ◽  
Bed Shear Stress ◽  
Breadth Ratio ◽  
Computational Fluid Dynamics Cfd ◽  
Simulated Flow

Research was undertaken in order to identify possible methodologies for the prediction of sedimentation in storage chambers based on computational fluid dynamics (CFD). The Fluent CFD software was used to establish a numerical model of the flow field, on which further analysis was undertaken. Sedimentation was estimated from the simulated flow fields by two different methods. The first approach used the simulation to predict the bed shear stress distribution, with deposition being assumed for areas where the bed shear stress fell below a critical value (τcd). The value of τcd had previously been determined in the laboratory. Efficiency was then calculated as a function of the proportion of the chamber bed for which deposition had been predicted. The second method used the particle tracking facility in Fluent and efficiency was calculated from the proportion of particles that remained within the chamber. The results from the two techniques for efficiency are compared to data collected in a laboratory chamber. Three further simulations were then undertaken in order to investigate the influence of length to breadth ratio on chamber performance. The methodology presented here could be applied to complex geometries and full scale installations.

scholarly journals Particle Responses to Near-Bed Shear Stress in a Shallow, Wave- and Current-Driven Environment

2021 ◽  
Author(s):  
Grace Chang ◽  
Galen Egan ◽  
Joseph D McNeil ◽  
Samuel McWilliams ◽  
Craig Jones ◽  
...  
Keyword(s):  
Shear Stress ◽  
Bed Shear Stress

scholarly journals Study on bed shear stress around channel constriction.

1985 ◽  
pp. 115-121
Author(s):  
Susumu HASHIMOTO ◽  
Yoshitaka FUKUI ◽  
Hideo KIKKAWA
Keyword(s):  
Shear Stress ◽  
Bed Shear Stress ◽  
Channel Constriction

scholarly journals Flow Visualization in a Simulated Brush Seal

1990 ◽  
Author(s):  
M. J. Braun ◽  
R. C. Hendricks ◽  
V. Canacci
Keyword(s):  
Flow Visualization ◽  
Flow Fields ◽  
Inlet Pressure ◽  
Complex Flow ◽  
Axial Pressure ◽  
Interface Motion ◽  
Pressure Profiles ◽  
Brush Seal ◽  
Brush Seals

A method to visualize and characterize the complex flow fields in simulated brush seals is presented. The brush seal configuration was tested in a water and then in an oil tunnel. The visualization procedure revealed typical regions that are rivering, jetting, vortical or lateral flows and exist upstream, downstream or within the seal. Such flows are engendered by variations in fiber void that are spatial and temporal and affect changes in seal leakage and stability. While the effects of interface motion for linear or cylindrical configurations have not been considered herein, it is believed that the observed flow fields characterize flow phenomenology in both circular and linear brush seals. The axial pressure profiles upstream, across and downstream of the brush in the oil tunnel have been measured under a variety of inlet pressure conditions and the ensuing pressure maps are presented and discussed.

The influence of deposit body on the near-bed shear stress

2021 ◽  
pp. 1-29
Author(s):  
Yan He ◽  
Jing Zhang ◽  
Huling Jiang ◽  
Zhixue Guo ◽  
Hongxi Zhao
Keyword(s):  
Shear Stress ◽  
Bed Shear Stress

A Rapid Viscous-Inviscid Interaction Method for the Preliminary Design of S-Shaped Transition Ducts

2021 ◽  
Author(s):  
A. Veyrat ◽  
J. F. Carrotte ◽  
A. D. Walker ◽  
C. Hall ◽  
H. Simpson
Keyword(s):  
Shear Stress ◽  
Rapid Assessment ◽  
Layer Growth ◽  
Preliminary Design ◽  
Interaction Method ◽  
Complex Flow ◽  
Potential Core ◽  
Law Of The Wall ◽  
Streamline Curvature ◽  
Use Of Time

Abstract For preliminary design of compressor transition ducts, knowledge-based tools for the rapid assessment of aerodynamic performance of S-shaped ducts are not currently available in the open literature. This is due to the highly complex flow developing under the combined influence of pressure gradients and streamline curvature. This paper presents a new approach enabling an agile design process avoiding premature use of time-consuming high-fidelity CFD calculations. The features of a 2D axisymmetric incompressible steady flow field are captured with a semi-analytical viscous inviscid interaction method. A potential core, based on streamline curvature and implicit velocity profile by parametric spline reconstruction, is coupled to an integral method predicting the turbulent boundary layer growth up to separation. The shear stress distribution is generated by a modified mixing length model for strongly curved flows and wall shear stress closure is performed by inverse calculation of a composite law-of-the-wall. When compared to CFD, the aerodynamic loading is generally predicted to within ±3% but convergence is achieved 20 times faster.

Sign in / Sign up

Export Citation Format

Share Document