The discharge rate of coarse powders (mean particle size >500 pm) from bunkers without aeration can be described by both empirical relations and theoretical models. In the case of small particles the discharge rate is largely overestimated. As the powder dilates during flow a negative pressure gradient develops near the hopper outlet, inducing an air flow into the hopper. This extra drag force ...

In this paper, the flow characteristics due to asymmetric sudden contraction is discussed based on experimental investigation when the flow through the contracted section passed from subcritical to critical flow. The experiments are conducted on a 30 cm wide, 45 cm deep and 10.5 m long laboratory flume. Different contraction ratios are considered. Different lengths of the contracted section are...

Side weir is a type of weirs that used extensively in a variety ofengineering projects such as river engineering, dam,waste water , Irrigation and drainage network. So the study on the flow characteristics on the type weir, is one of the mostimportant topics in hydraulic engineering. The spatially varied flow (S.V.F)with discharge decreasing is governing equation to this type weir.Study on the ...

This research aims to study jet downstream scour model under the influence of changes of water level. It also studies and analyzes different parameters and components of diffusion of submerged jet flow in an acceptor fluid and scour hole dimensions. To achieve the objectives, a physical model was made in proportion to the research title. With the Froude number increasing in a nozzle discharge, ...

Nowadays, developed and applied hydrology become very important thing in the life due to the wide verity advantages for the applications of this field. Hydraulic Structures such as crump weir are placed in channels to estimate or measure flow rate and flow control devices. In this study there is a new performance for crump weir which appears by adding opening holes in the model  of crump weir. ...

Ammonium (NH4 ), nitrate+nitrite (NOx), dissolved inorganic phosphorus (DIP) and dissolved organic carbon, nitrogen and phosphorus (DOC, DON and DOP) were measured in the Altamaha River and several tributaries during a two year period from September 2000 through September 2002. Temporal variations in concentration as well as nutrient and dissolved organic matter loading from the Altamaha to the...

A computer model for prediction and analysis of an oil-flooded single screw compressor performance is developed. The model includes suction preheat, pressuri ~~.tion of the gas in the control volume during the suction closure process, flowage of gas and oil mixture through discharge port, leakage of gas and oil. It considers the effect of oil-injection rate, clearances and length of leaka~e pat...

Our objective was to quantify the contribution of autochthonous, locally-produced phytoplankton, and allochthonous, terrestrial-derived organic matter (OM) to the production of young-of-year (YOY) American shad (Alosa sapidissima) using stable isotopes. We measured the carbon and nitrogen stable isotope composition of YOY American shad in the tidal fresh water of the Mattaponi River, a tributar...

An experimental investigation is conducted on simultaneous flow through culvert and over broad-crested weir. The flow at the culvert outlet is considered as submerged flow. Both the culvert and the broad-crested weir (BCW) widths are smaller than the channel width. The characteristics of the simultaneous flow through both structures and the effects of flow and geometrical parameters of the stru...