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hydrological-regime
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Assessment of 2DH and pseudo-3D modelling platforms in a large saline aquatic system: Lake Urmia, Iran
, Article Hydrological Processes ; Vol. 28, Issue. 18 , 2014 , pp. 49534970 ; ISSN: 10991085 ; Tofighi, M. A ; Bakhtiari, A ; Sharif University of Technology
Abstract
The main objective of this paper is to provide comparative quantitative examinations on the capabilities of two-dimensional horizontal and pseudo-three-dimensional (3D) modelling approaches for simulating spatial and temporal variability of the flow and salinity in Lake Urmia, Iran. The water quality in the lake has been an environmentally important subject partly because this shallow hypersaline aquatic ecosystem is considered to be one of the largest natural habitats of a unique multicellular organism, Artemia urmiana. This brine shrimp is the major food source for many of the protected and rare shorebirds that visit the lake. A.urmiana can grow and survive in certain ranges of salinity,...
Water allocation for wetland environmental water requirements: The case of Shadegan wetland, Jarrahi catchment, Iran
, Article World Environmental and Water Resources Congress 2006: Examining the Confluence of Environmental and Water Concerns, Omaha, NE, 21 May 2006 through 25 May 2006 ; 2007 ; 0784408564 (ISBN); 9780784408568 (ISBN) ; Tajrishy, M ; Sharif University of Technology
2007
Abstract
The Shadegan Wetland is a Ramsar-listed wetland in the south-west of Iran at the head of the Persian Gulf. It is the largest wetland of Iran covering about 400,000 hectares. The wetland plays a significant hydrological and ecological role in the natural functioning of the northern Gulf. It also supports a very diverse flora and fauna and is the most important site in the world for Marbled Teal. The water regime is threatened by upstream abstraction of water for irrigation and the saline discharge from sugar cane industries and irrigation schemes. This will result in an overall reduction in wetland water quantity and quality, leading to a change in plant community composition. This paper...
Experimental investigation of air-water, two-phase flow regimes in vertical mini pipe
, Article Scientia Iranica ; Volume 18, Issue 4 B , August , 2011 , Pages 923-929 ; 10263098 (ISSN) ; Saidi, M. H ; Nouri Gheimasi, A ; Ghanbarzadeh, S ; Sharif University of Technology
2011
Abstract
In this study, the flow patterns of air-water, two-phase flows have been investigated experimentally in a vertical mini pipe. The flow regimes were observed by a high speed video recorder in pipes with diameters of 2,3 and 4 mm and length 27, 31 and 25 cm, respectively. The comprehensive visualization of air-water, two-phase flow in a vertical mini pipe has been performed to realize the physics of such a two-phase flow. Different flow patterns of air-water flow were observed simultaneously in the mini pipe at different values of air and water flow rates. Consequently, the flow pattern map was proposed for flow in the mini-pipe, in terms of superficial velocities of liquid and gas phases. The...
Modeling of twin-entry radial turbine performance characteristics based on experimental investigation under full and partial admission conditions
, Article Scientia Iranica ; Volume 16, Issue 4 B , 2009 , Pages 281-290 ; 10263098 (ISSN) ; Rad, M ; Shahhosseini, M. R ; Sharif University of Technology
2009
Abstract
In this paper, the performance of a turbocharger twin-entry radial inflow turbine is investigated analytically and experimentally under steady state, full and partial admission conditions. In this modeling, the mass flow rate, pressure ratio and efficiency of the turbine are assumed unknown. The turbine geometry and the inlet total pressure and temperature are known, hence, the turbine performance characteristics can be obtained. In the turbocharger laboratory, performance characteristics of the turbine are determined, measuring the main parameters for various operating conditions. Comparing the model and experimental results shows good agreement. Also, considering the effect of test...