many experimental studies have been conducted on development of the scour hole as a result of vertical jet impaction. research has shown that aeration of the nappe flow in the model is much weaker than that in the prototype. therefore, the influence of aeration on scour holes needs further study. experimental investigation of the effects of air entrainment and tail water depth on the scour hole...

Local scouring around bridge piers is a natural phenomenon caused by the erosive process of flowing stream on alluvial beds. The 3D flow field around bridge piers interacting with the bed materials increases complexity of local scour process. The local scour depth develops in accelerated flows and if it is not predicted correctly, the bottom level of local scour hole will exceed the original le...

A scour monitoring system for subsea pipeline based on active thermometry is proposed in this paper. The temperature reading of the proposed system is based on a distributed Brillouin optical fiber sensing technique. A thermal cable acts as the main component of the system, which consists of a heating belt, armored optical fibers and heat-shrinkable tubes which run parallel to the pipeline. Th...

scour around hydraulic structures is an inevitable phenomenon . recognition of this phenomenon and dealing with it is an issue considering which will ensure the project success . local scour at piers has been reported as the most important factor in the destruction of the bridges . the use of submerged and non-submerged piles is one of the scour control methods . submerged piles have been rarel...

in this paper the effectiveness combination of bed sill and collar in reduction of local scour depth at cylindrical piers under clear water flow condition was investigated (v/vc=0.9). in the first of experiments, the bed sill was located in downstream and different distances from the piers. results indicated that minimum distance of the bed sill from the piers in downstream has maximum reductio...

Failures of barrages or regulators or parts of them may be expected when excessive scour patterns are observed downstream of such structures. Severe and excessive scour may be largely due to unsymmetric operation of gates especially when a multi-vents barrages or regulator is being considered. Previous investigations proved that the scour patterns downstream hydraulic structures are functions o...

I . Piglets were left to suckle their dam for about z days after birth to obtain colostrum and were then divided into four groups. One group was left with the sow, the second was given a standard liquid diet based on cow’s milk, the third the standard diet with lactic acid added to give a pH of 4.8, and the fourth the standard diet with the casein content increased by 50 yo. Stomach samples wer...

abstract the groines are structures which are use to protected the river bank and to form the water way .the most important problem of groynes is scour at around it that makes breaking and overturning the groynes. because of the less researches at about l-head groynes and open groynes ,this article considers the amount of scour in this type of groynes. so because of this have been used the lace...

A major goal of the ONR Mine Burial Prediction (MBP) Program is to provide the operational Navy simple models for predicting subsequent mine burial by scour which work with a known and useful degree of accuracy in regions of strategic interest, defined initially as sandy inner shelves dominated by waves. In order to be useful under real world conditions, such models must be reasonably accurate ...

Two sets of experiments related to the scour of cohesionless sediment by planar turbulent jets are presented and discussed. The first set of experiments measures the growth of the scour hole and downstream dune as a function of time. Measurements reveal a bedform that is nearly self-similar and whose growth in time is governed by a power-law relationship. The bedform is well represented by thre...