scholarly journals Influence of Scour Development on Turbulent Flow Field in Front of a Bridge Pier

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2370
Author(s):  
Jinzhao Li ◽  
Yilin Yang ◽  
Zhiwen Yang
Keyword(s):  
Flow Field ◽  
Turbulent Flow ◽  
Reynolds Shear Stress ◽  
Bridge Pier ◽  
Scour Depth ◽  
Image Velocimetry ◽  
Scour Hole ◽  
Practical Engineering ◽  
Turbulent Flow Field ◽  
Variation Tendency

This study concerns the turbulent flow field influenced by the scour development around a bridge pier. The scour hole evolution as well as the temporal variation of scour depth around the pier were firstly analyzed. Subsequently, the flow fields in front of the pier at different instants during the scour process were measured using particle image velocimetry (PIV). It shows that the scour depth at the pier front exceeds that of the pier side at the later scouring stage. The temporal development of scour depth can be well predicted by a simple practical engineering model based on an exponential function with a change in the two adjustable coefficients. The flow field indicates that with the development of scour hole, the downward flow in front of the pier becomes more prominent, meanwhile the flow becomes more turbulent. The variation tendency for both velocities and turbulence intensities along the streamwise direction in front the pier shows similarity. The Reynolds shear stress generally increases with developing scour hole, and the region with large value enlarges and moves upstream of the scour hole.

Turbulent flow field in a scour hole at a semicircular abutment

2005 ◽  
Vol 32 (1) ◽  
pp. 213-232 ◽  
Author(s):  
Subhasish Dey ◽  
Abdul Karim Barbhuiya
Keyword(s):  
Flow Field ◽  
Turbulent Flow ◽  
Three Dimensional ◽  
Shear Stresses ◽  
Reynolds Stresses ◽  
Primary Vortex ◽  
Scour Hole ◽  
Turbulent Flow Field ◽  
Development And Validation ◽  
Bed Shear Stresses

The three-dimensional turbulent flow field in a scour hole at a semicircular abutment under a clear water regime was experimentally measured in a laboratory flume using an acoustic Doppler velocimeter. The distributions of time-averaged velocity components, turbulent intensity components, turbulent kinetic energy, and Reynolds stresses at different azimuthal planes are presented. Upstream, presentation of flow field through vector plots at azimuthal and horizontal planes shows the existence of a large primary vortex associated with the downflow inside the scour hole. On the other hand, downstream, the flow field is irregular. The bed shear stresses are determined from the Reynolds stresses and velocity gradients. The data presented in this paper would be useful for the development and validation of flow field models, which can be used to determine the strength of the primary vortex that is used to estimate scour depth at bridge abutments.Key words: bridge abutments, fluid flow, three-dimensional flow, turbulent flow, open channel flow, scour, sediment transport, hydraulic engineering.

Numerical simulations and analysis of the turbulent flow field in a practical gas turbine engine combustor

2021 ◽  
pp. 095765092110632
Author(s):  
Veeraraghava R Hasti ◽  
Prithwish Kundu ◽  
Sibendu Som ◽  
Jay P Gore
Keyword(s):  
Flow Field ◽  
Turbulent Flow ◽  
Numerical Simulations ◽  
Gas Turbine ◽  
Adaptive Mesh Refinement ◽  
Three Dimensional ◽  
Adaptive Mesh ◽  
Turbulent Structures ◽  
Cut Cell ◽  
Turbulent Flow Field

The turbulent flow field in a practical gas turbine combustor is very complex because of the interactions between various flows resulting from components like multiple types of swirlers, dilution holes, and liner effusion cooling holes. Numerical simulations of flows in such complex combustor configurations are challenging. The challenges result from (a) the complexities of the interfaces between multiple three-dimensional shear layers, (b) the need for proper treatment of a large number of tiny effusion holes with multiple angles, and (c) the requirements for fast turnaround times in support of engineering design optimization. Both the Reynolds averaged Navier–Stokes simulation (RANS) and the large eddy simulation (LES) for the practical combustor geometry are considered. An autonomous meshing using the cut-cell Cartesian method and adaptive mesh refinement (AMR) is demonstrated for the first time to simulate the flow in a practical combustor geometry. The numerical studies include a set of computations of flows under a prescribed pressure drop across the passage of interest and another set of computations with all passages open with a specified total flow rate at the plenum inlet and the pressure at the exit. For both sets, the results of the RANS and the LES flow computations agree with each other and with the corresponding measurements. The results from the high-resolution LES simulations are utilized to gain fundamental insights into the complex turbulent flow field by examining the profiles of the velocity, the vorticity, and the turbulent kinetic energy. The dynamics of the turbulent structures are well captured in the results of the LES simulations.

Turbulent flow-field effects in a hybrid CFD-CRN model for the prediction of NO and CO emissions in aero-engine combustors

Fuel ◽  
2018 ◽  
Vol 215 ◽  
pp. 853-864 ◽  
Author(s):  
A. Innocenti ◽  
A. Andreini ◽  
D. Bertini ◽  
B. Facchini ◽  
M. Motta
Keyword(s):  
Flow Field ◽  
Turbulent Flow ◽  
Field Effects ◽  
Aero Engine ◽  
Turbulent Flow Field
Sign in / Sign up

Export Citation Format

Share Document