Groyne

About: Groyne is a research topic. Over the lifetime, 397 publications have been published within this topic receiving 4549 citations. The topic is also known as: groin & Breakwater.

Flow Resistance of Vegetated Weirlike Obstacles during High Water Stages

Abstract: The objective of this study is to estimate, model, and parameterize the form drag due to vegetated weirlike obstacles. An experimental study has been carried out for validation purposes. The prototype weirlike structure (in the form of a dike or groyne) has been modeled as a weir with various downstream slopes (1:4, 1:7, 1:15), and vegetation has been represented in various shapes placed on top of the crest of the weir with 25% blockage area inside the vegetated region. Measurements for energy head losses are carried out for a range of discharges and downstream water levels covering submerged and subcritical flow conditions. The energy head loss attributable to submerged vegetated dikes and groynes can be modeled well by an expansion loss form drag model, which is based on a one-dimensional energy and momentum conservation equations.

Groyne spacing role on the effective control of wall shear stress in open-channel flow

Abstract: The objective of an effective configuration for a series of groynes in an open channel is the attainment of large bed shear stress in the main channel for channel deepening and small sidewall shear...

Investigation of Vorticity Effects on Local Scouring

Abstract: This paper describes a numerical model developed to simulate flow and bed deformation around hydraulic structures. The model uses an improved formula for the bed shear stress by applying vorticity effect and solves the full three-dimensional Reynolds-averaged Navier–Stokes equations to calculate the flow field. The capability for numerical models to predict local scour is severely restricted by the sediment transport formula. Up to now, the scour computations were developed based on general sedimentation formula through a straight unobstructed flow path. The new sedimentation formula introduced in this paper can take into account vortices that affect the local scour process. To verify the model, a bridge pier and a groyne, which are considered as typical river-engineering structures, were simulated in different hydraulic conditions by applying both the ordinary bed shear stress equation and the new one. Comparisons show that the new equation could predict the scour more accurately than the ordinary one.

An Experimental Study on Tip Velocity and Downstream Recirculation Zone of Single Groyne Conditions

Abstract: Recently, the concern of groynes that provide us with various ecological environment and improvement of scenary near river as well as hydraulic improvement has greatly increased for naturalized river and ecological river restoration. However there is no adequate design guidelines in Korea. Furthermore there is lack of research for installation of groynes in Korea. Thus, in this study, we have conducted hydraulic modeling test for kinds of groyne and changes of permeability and made a study of the analysis for installation factor of groyne. Experimental conditions were the fixed bed model for flow pattern of groyne tip and separation length about changes of groyne length and permeability. The Experiments were conducted to measure velocity and drift angle at groyne tip. The main study kas measured the groyne tip velocity for a factor of scour and drift angle for velocity increase at center of channel. We have suggested the equation about groyne tip velocity rate(tip velocity/ approach velocity) and area rate(groyne area/ flow area). And In recirculation zone of groyne downstream, To study the basic data of groyne about installation interval has analyzed the change of separation length and incidence angle. We have suggested the equation about separation length rate(separation length/ groyne length), changes of permeability and installation angle.