filter is one of the main components of embankment dams. by a simple but effective performance, filter protects the dam against erosion and soil scouring in impervious core caused by leakage (piping) and makes it safe. interaction between filter and erodible base soil is a complex phenomenon which is dependent upon several factors, and has challenged researchers for better understanding the fil...

Laboratory studies have indicated that calcite may be used in separate, exchangeable filter units in constructed wetland systems to remove phosphorus. Based on these studies we built a full-scale experimental constructed wetland with a calcite-based filter unit to study its performance, under real-life conditions. The system consists of a 2-m3 sedimentation tank and two vertical flow constructe...

in this paper, a finite element model is developed for the fully hydro-mechanical analysis of hydraulic fracturing in partially saturated porous media. the model is derived from the framework of generalized biot theory. the fracture propagation is governed by a cohesive fracture model. the flow within the fracture zone is modeled by the lubrication equation. the displacement of solid phase, and...

throughout history dams have been important structures in water storage. to avoid overtopping, damage, and or failure of a dam, adequate spillway is needed to release excess water from upstream floods. researchers found that spillways have to be made nonlinear in order to reach an economic structure with high performance. a piano key weir is one of the best solutions. piano key weirs are the mo...

a down-flow hanging sponge (dhs) reactor has been developed for sewage treatment, mainly in developing countries. this novel reactor employs polyurethane sponge material as a support medium, which promises a proliferation of a large amount of biomass, offering excellent pollutant removal capability. three types of sponge medium were evaluated with respect to water distribution and oxygen mass t...

Hydraulic researchers had been leading air–water flow studies until the mid-1950s. Since progresses have been dominated by multiphase flow experts despite the relevance of “white water” phenomena to hydraulic engineering. In this lecture the writer reviews the basic mechanisms of air entrainment: singular aeration and interfacial entrainment. The relevant instrumentation and data processing tec...

A PIV study of the flow in a stationary model of a smooth two-pass internal coolant passage is presented, which focuses on the flow characteristics in the sharp 180o bend and downstream of the bend where the flow is redeveloping. Because PIV in its traditional conception only allows for the investigation of two-dimensional flow, a stereoscopic digital PIV system was assembled that measures all ...

We present a simple viscous theory of free-surface flows in boundary layers, which can accommodate regions of separated flow. In particular this yields the structure of stationary hydraulic jumps, both in their circular and linear versions, as well as structures moving with a constant speed. Finally we show how the fundamental hydraulic concepts of subcritical and supercritical flow, originatin...

This paper denouements the study of operating parameters of a hydraulic transmission system with and without the application of hydraulic accumulator. In this respect, the hydraulic system, designed in the open circuit mode, consists of the fixed displacement hydraulic pump which gives pressured fluid to the hydro-motor and charges the accumulator as well. The load on the motor is controlled hy...