An Experimental Study on Cross-Shore Sediment Transport

The cross-shore sediment transport in a coastal region causes the important changes in beach morphological properties. The accurate estimation of the cross-shore sediment transport is important for the designing of the marine structures such as seawalls, jetties, breakwaters etc, and the preventing coastal erosion and accretion due to on-off shore sediment transportation. In this study, the experiments on cross- shore sediment transport carried out in a laboratory wave channel for initial beach slopes of 1/8, 1/10 and 1/15. Using the regular waves with different deep-water wave steepness generated by a pedal-type wave generator, the geometrical characteristics of beach profiles under storm conditions and the parameters affecting on-off shore sediment transport are investigated for the beach materials having medium diameters of d50=0.25, 0.32, 0.45, 0.62 and 0.80 mm. The experimental results obtained from this study compared with previous experimental work and found to be of the same magnitude as the experimental measurements and followed the expected basic trend

Investigation of vortical flow characteristics around a partially buried circular cylinder

The interaction of vortical flow with a cylindrical structure is encountered in a variety of engineering applications. Determination of the affected flow structure in terms of its kinematics and related properties is important for the study of fluid-body interaction problems. In this study, the PIV technique is used to measure the velocity field of two-dimensional turbulent flow around a partially buried circular cylinder on a smooth plane boundary. Experiments are conducted in a closed-loop water channel for flow conditions with Reynolds numbers based on the cylinder diameter, ReD=1000, 3000, 5000 and 7000. Instantaneous and time-averaged patterns of velocity vectors, corresponding streamline topology, vorticity contours and distributions of turbulence statistical quantities are presented for the burial ratios, B/D=0.25 and B/D=0.50 to provide a detailed evaluation of the vortical flow characteristics. Moreover, the effect of burial ratio on the wall boundary-layer separation upstream and downstream of the circular cylinder and, the positions of the separation points on the cylinder surface are investigated. © 2012 Elsevier Ltd.MMF2011BAP5The work was partly supported by the Cukurova University Research Fund under project no: MMF2011BAP5 . This support is gratefully acknowledged

Experimental and Numerical Modeling of Submerged Hydraulic Jump Downstream of a Sluice Gate

WOS: 000318454300003Experimental and Numerical Modeling of Submerged Hydraulic Jump Downstream of a Sluice Gate The flow profile in an open channel model with submerged hydraulic jump downstream of a vertical sluice gate is measured for flow cases with Fr-1=1.77 and 1.35. The governing equations are numerically solved using Finite Volume method for the flows having the same conditions with experiments. In the numerical simulations, Standard k-epsilon, Renormalization-group k-epsilon and Realizable k-epsilon turbulence closure models are employed. Experimental validations of the numerical results show that computations using Renormalization-group k-epsilon turbulence model are the most successful, among the three, in predicting the free surface of the flow and the geometry of the submerged hydraulic jump

Experimental and Numerical Analysis of Flow around a Circular Bridge Pier

WOS: 000444153900017The turbulent flow field around a circular pier is complex due to separation and generation of multiple vortices in different structures. This topic has a great interest in engineering applications for the design of the bridges over water. In this study, the velocity field of flow around a circular pier is measured using Laser Doppler Anemometry (LDA). The Basic equations of the problem are solved by ANSYS-Fluent program package based on finite volume method for the flow case having the same experimental conditions. In the numerical simulations, Standard k-epsilon, Renormalization Group k-epsilon and Realizable k-epsilon turbulence closure model are used for the simulation of turbulence, and the flow profile is computed using Volume of Fluid method. Grid Convergence Index (GCI) is performed to examine the effect of the selected grid structure on the numerical results. The computed results for velocities and free surface profiles are compared with measured data. The comparisons of the experimental and numerical results show that Realizable k-epsilon is more successful turbulence model among the other models in predicting the velocity field and free surface profiles

Numerical Modeling of Interaction of Turbulent Flow with a Buried Circular Cylinder on a Plane Surface

WOS: 000494262000005Turbulent flow characteristics around a partially buried horizontal circular cylinder are investigated numerically for the burial ratio of B/D=0.50 (B is burial depth, D is the diameter of the cylinder). The governing equations are numerically solved using ANSYS-Fluent for the flows having the same conditions with the experiments related to measurements of velocity field by Particle Image Velocimetry for Reynolds numbers based on the cylinder diameter, in the ranges of 1000 <= Re-D <= 7000. Standard k-epsilon, Renormalization-group k-epsilon, Realizable k-epsilon, Modified k-omega, Shear Stress Transport k-omega and Reynolds Stress turbulence models are employed. Experimental validations of the numerical results show that Shear Stress Transport k-omega model provides better predictions for the kinematic properties of the turbulent flow than the other turbulence models used herein. Force coefficients also predicted numerically at Reynolds numbers in the ranges of 1000 <= Re-D <= 7000 for the burial ratio, B/D=0, 0.25 and 0.5

Closure to "Numerical modeling of submerged hydraulic jump from a sluice gate" by Veysel Gumus, Oguz Simsek, Nazire Goksu Soydan, Mevlut Sami Akoz, and Mehmet Salih Kirkgoz

[No abstract available