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Parapet walls on the crown of piano key weirs (PKW) are employed in the channels to regulate or increase water levels of the upstream. They are also used in the reservoirs to increase water storage. Most recent surveys concerning discharge coefficient and parapet walls have been conducted on the rectangular piano key weirs (RPKW) while not many of them devoted to trapezoidal piano key weirs (TPKW). Also, the effects of its parapet wall and crest shape are rarely investigated in this regard. The aim of this research was to study the impacts of height (R), installation arrangements (S), and crest shape of parapet walls (flat, triangular, and semicircular) on changes of the upstream water level and discharge coefficient of TPKW. The weir height (P) was 15 cm. The parapet walls were installed on the crest of weir with three different arrangements: S1 (on the crest overall), S2 (on the sidewalls and inlet key), and S3 (on the sidewalls). The results indicated that the influence of installation arrangement on changes of water level increased with the growth of parapet walls height. In the case of a flat parapet walls, maximum and minimum increase rates of total head were recorded for S1 and S3 arrangements, respectively. There was also a direct relationship between discharge coefficient (C) and the heights of parapet walls in a constant water level at upstream. When installing flat parapet walls with R/P = 0.3, the value of C for S2 exceeded those for S1 and S3.
Mostafa Akbari Kheir-Abadi; Mehdi Karami Moghadam; Touraj Sabzevari; Zahra Ghadampour. An experimental study of the effects of the parapet walls geometry on the discharge coefficient of trapezoidal piano key weirs. Flow Measurement and Instrumentation 2020, 73, 101742 .
AMA StyleMostafa Akbari Kheir-Abadi, Mehdi Karami Moghadam, Touraj Sabzevari, Zahra Ghadampour. An experimental study of the effects of the parapet walls geometry on the discharge coefficient of trapezoidal piano key weirs. Flow Measurement and Instrumentation. 2020; 73 ():101742.
Chicago/Turabian StyleMostafa Akbari Kheir-Abadi; Mehdi Karami Moghadam; Touraj Sabzevari; Zahra Ghadampour. 2020. "An experimental study of the effects of the parapet walls geometry on the discharge coefficient of trapezoidal piano key weirs." Flow Measurement and Instrumentation 73, no. : 101742.
The present research was carried out to study drought and its effects upon water resources using remote sensing data. To this end, the tropical rainfall measuring mission (TRMM) satellite precipitation, the synoptic stations, and fountain discharge data were employed. For monitoring of drought in the study area, in Kermanshah province, Iran, the monthly precipitation data of the synoptic stations along with TRMM satellite precipitation datasets were collected and processed in the geographic information system (GIS) environment. Statistical indicators were applied to evaluate the accuracy of TRMM precipitation against the meteorological stations’ data. Standardized precipitation index, SPI, and normalized fountain discharge were used in the monitoring of drought conditions, and fountains discharge, respectively. The fountains were selected so that in addition to enjoying the most discharge rates, they spread along the study area. The evaluation of precipitation data showed that the TRMM precipitation data were of high accuracy. Studies in temporal scale are indicative of the strike of drought in this region to the effect that for most months of the year, frequency and duration in dry periods are much more than in wet periods. As for seasonal scales, apart from winter, the frequency and duration of drought in spring and autumn have been longer than in wet years. Moreover, the duration of these periods was different. A comparison between the results of changes in fountain discharges and drought index in the region has verified that the drought has caused a remarkable decline in the fountain discharges.
Ata Amini; Abdolnabi Abdeh Kolahchi; Nadhir Al-Ansari; Mehdi Karami Moghadam; Thamer Mohammad. Application of TRMM Precipitation Data to Evaluate Drought and Its Effects on Water Resources Instability. Applied Sciences 2019, 9, 5377 .
AMA StyleAta Amini, Abdolnabi Abdeh Kolahchi, Nadhir Al-Ansari, Mehdi Karami Moghadam, Thamer Mohammad. Application of TRMM Precipitation Data to Evaluate Drought and Its Effects on Water Resources Instability. Applied Sciences. 2019; 9 (24):5377.
Chicago/Turabian StyleAta Amini; Abdolnabi Abdeh Kolahchi; Nadhir Al-Ansari; Mehdi Karami Moghadam; Thamer Mohammad. 2019. "Application of TRMM Precipitation Data to Evaluate Drought and Its Effects on Water Resources Instability." Applied Sciences 9, no. 24: 5377.
The effects of changes in the angle of pool impact plate, plunging depth, and discharge upon the dynamic pressure caused by ski-jump buckets were investigated in the laboratory. Four impact plate angles and four plunging depths were used. Discharges of 67, 86, 161, and 184 L/s were chosen. For any discharge, plunging depth and impact plate angle were regulated, and dynamic pressures were measured by a transducer. The results showed that with the increase in the ratio of drop length of the jet to its break-up length (H/Lb), and with an increase in the impact plate angle, the mean dynamic pressure coefficient decreased. An inspection of the plunging depth (Y) ratio to the initial thickness of the jet (Bj) revealed that when Y/Bj > 3, the plunging depth of the downstream pool reduced dynamic pressure. At the angle of 60°, the dynamic pressure coefficient due to increasing in plunging depth varied from 34% to 95%.
Mehdi Karami Moghadam; Ata Amini; Marlinda Abdul Malek; Thamer Mohammad; Hasan Hoseini. Physical Modeling of Ski-Jump Spillway to Evaluate Dynamic Pressure. Water 2019, 11, 1687 .
AMA StyleMehdi Karami Moghadam, Ata Amini, Marlinda Abdul Malek, Thamer Mohammad, Hasan Hoseini. Physical Modeling of Ski-Jump Spillway to Evaluate Dynamic Pressure. Water. 2019; 11 (8):1687.
Chicago/Turabian StyleMehdi Karami Moghadam; Ata Amini; Marlinda Abdul Malek; Thamer Mohammad; Hasan Hoseini. 2019. "Physical Modeling of Ski-Jump Spillway to Evaluate Dynamic Pressure." Water 11, no. 8: 1687.
Physical modelling was used to assess the effects of the inlet shape, angle, diverted flow discharge and submerged vanes on the rate of sediment entry, erosion and shear stress of the intake. Experiments were conducted in a 55−degree intake channel branched from a rectangular channel. The mouth of the intake was chosen in two forms of sharp and rounded edge. Sedimentation and erosion values were measured in discharges of 11 and 16.6 l/s in the main channel with the four diversion flow ratios as 0.2, 0.4, 0.6 and 0.8. The submerged vanes were used in parallel and zigzag arrangements at angles of 10° and 30°. The results showed that making the mouth of the intake as rounded edge causes increase in the erosion and decrease in the sedimentation and hence reduction in deposited sediments. The shear stress was less in the presence of submerged vanes compared to the mode without installing the vanes.
Mehdi Karami Moghadam; Ata Amini; Alireza Keshavarzi. Intake design attributes and submerged vanes effects on sedimentation and shear stress. Water and Environment Journal 2019, 34, 374 -380.
AMA StyleMehdi Karami Moghadam, Ata Amini, Alireza Keshavarzi. Intake design attributes and submerged vanes effects on sedimentation and shear stress. Water and Environment Journal. 2019; 34 (3):374-380.
Chicago/Turabian StyleMehdi Karami Moghadam; Ata Amini; Alireza Keshavarzi. 2019. "Intake design attributes and submerged vanes effects on sedimentation and shear stress." Water and Environment Journal 34, no. 3: 374-380.
The study of flow patterns in front of intake has been attracted the attention of researchers during the past decades to explore the mechanism of flow and sediment entry to the intake. In this study, the separation and stream tube dimensions were investigated in water intakes installed to rectangular and ...
S. M. Seyedian; Mehdi Karami Moghadam; Y. Ramezani. Numerical Analysis of Separation and Stream tube Dimensions in the Intakes Installed to Rectangular and Trapezoidal Channels. Journal of Water and Soil Science 2018, 21, 129 -141.
AMA StyleS. M. Seyedian, Mehdi Karami Moghadam, Y. Ramezani. Numerical Analysis of Separation and Stream tube Dimensions in the Intakes Installed to Rectangular and Trapezoidal Channels. Journal of Water and Soil Science. 2018; 21 (4):129-141.
Chicago/Turabian StyleS. M. Seyedian; Mehdi Karami Moghadam; Y. Ramezani. 2018. "Numerical Analysis of Separation and Stream tube Dimensions in the Intakes Installed to Rectangular and Trapezoidal Channels." Journal of Water and Soil Science 21, no. 4: 129-141.
Alireza Keshavarzi; Mehdi Karami Moghadam; James E. Ball. Optimising round-edged entrance of 55° river water intake. Water Management 2012, 165, 9 -19.
AMA StyleAlireza Keshavarzi, Mehdi Karami Moghadam, James E. Ball. Optimising round-edged entrance of 55° river water intake. Water Management. 2012; 165 (1):9-19.
Chicago/Turabian StyleAlireza Keshavarzi; Mehdi Karami Moghadam; James E. Ball. 2012. "Optimising round-edged entrance of 55° river water intake." Water Management 165, no. 1: 9-19.
One of the problems at most water intakes is accumulation of sediment at the entrance and changing of flow talweg path at the water intake. Submerged vanes are small hydraulic structures that are used for flow and sediment control on the bed of rivers. The submerged vanes may be installed individually or in a group with different arrangements. In this study, a group of submerged vanes are installed at the entrance of a rounded edge 55° water intake with parallel and zigzag arrangements. The vanes' installation angles were selected to be 10, 20, 30 and 40° to the flow direction. The sedimentation pattern at the entrance of the water intake and the amount of sediment entering into the lateral channel were measured after experimental tests. From the experimental study, the optimum vane angle for the above‐specified water intake was found to be 30°. Also the parallel arrangement was found to be the best arrangement for the submerged vane. Copyright © 2009 John Wiley & Sons, Ltd. L'un des problèmes pour la plupart des prises d'eau est l'accumulation de sédiments à l'entrée et aux lieux de changement de débit. Les masques submergés sont de petites structures hydrauliques qui sont utilisées pour le contrôle des sédiments et des débits dans le lit des cours d'eau. Les masques submergés peuvent être installés individuellement ou en groupe avec différents arrangements. Dans cette étude, un groupe de masques submergés a été installé à l'entrée d'une prise d'eau à 55 degrés à bord arrondi avec une disposition parallèle et en zigzag. Les masques ont été installés à 10, 20, 30 et 40 degrés de la direction du flux. La forme de la sédimentation à l'entrée de la prise d'eau et la quantité de sédiments entrée dans le canal ont été mesurés après des essais expérimentaux. De l'étude expérimentale il ressort que le meilleur angle du masque pour cette prise d'eau est de 30 degrés. En outre la meilleure disposition pour le masque est la disposition en parallèle. Copyright © 2009 John Wiley & Sons, Ltd.
Mehdi Karami Moghadam; Ali Reza Keshavarzi. An optimised water intake with the presence of submerged vanes in irrigation canals. Irrigation and Drainage 2009, 59, 432 -441.
AMA StyleMehdi Karami Moghadam, Ali Reza Keshavarzi. An optimised water intake with the presence of submerged vanes in irrigation canals. Irrigation and Drainage. 2009; 59 (4):432-441.
Chicago/Turabian StyleMehdi Karami Moghadam; Ali Reza Keshavarzi. 2009. "An optimised water intake with the presence of submerged vanes in irrigation canals." Irrigation and Drainage 59, no. 4: 432-441.