Enhancement of flushed sediment in pressure flushing using inclined plates upstream of orifice

Pressure flushing is a common technique to restore the storage capacity of reservoirs. However, the low quantity of flushed sediment remains a drawback of pressure flushing. Experimentally, the present study used inclined plates upstream of the bottom outlet to increase the flushed sediment in press...

Full description

Bibliographic Details
Main Authors: Nima Najafi, Mehdi Daryaee, Seyed Mahmood Kashefipour
Format: Article
Language:English
Published: IWA Publishing 2022-10-01
Series:Water Supply
Subjects:
Online Access:http://ws.iwaponline.com/content/22/10/7701
_version_ 1811331565345570816
author Nima Najafi
Mehdi Daryaee
Seyed Mahmood Kashefipour
author_facet Nima Najafi
Mehdi Daryaee
Seyed Mahmood Kashefipour
author_sort Nima Najafi
collection DOAJ
description Pressure flushing is a common technique to restore the storage capacity of reservoirs. However, the low quantity of flushed sediment remains a drawback of pressure flushing. Experimentally, the present study used inclined plates upstream of the bottom outlet to increase the flushed sediment in pressure flushing. The variables included the plate width (B), the angel between the vertical line at the outlet center and the normal vector of the inclined plate (α), radial distance of the inclined plates from the orifice center (R), and outlet discharge (Q). The results showed that the flushed sediment significantly enhanced; the quantity of flushed sediment for B = 6.3 cm, α = 60°, R = 8.5 cm, and a Q = 8.34 L/s was 19 times as large as that in the reference test (i.e., without plates). Furthermore, the length, width, and depth of the scour cone in the presence of inclined plates were 3, 2.3, and 3.3 times as high as those in the absence of the inclined plates. Also, equations were developed to predict the volume and dimensions of the scour cone in the presence of inclined plates based on the experimental data. Finally, the importance of the variables was determined using a sensitivity analysis method. Between all considered parameters in this study, the plate distance from the outlet was found to have the highest effect and the plate inclination the lowest effect (three times) in increasing the flushed sediment through the orifice. HIGHLIGHTS Increasing pressure flushing efficiency.; Reducing discharged water volume during pressure flushing operation.; Prevention of sediment deposition close to bottom outlet.;
first_indexed 2024-04-13T16:22:33Z
format Article
id doaj.art-0cc87d9123f14083a19add7ea9ac5eb1
institution Directory Open Access Journal
issn 1606-9749
1607-0798
language English
last_indexed 2024-04-13T16:22:33Z
publishDate 2022-10-01
publisher IWA Publishing
record_format Article
series Water Supply
spelling doaj.art-0cc87d9123f14083a19add7ea9ac5eb12022-12-22T02:39:51ZengIWA PublishingWater Supply1606-97491607-07982022-10-0122107701771210.2166/ws.2022.340340Enhancement of flushed sediment in pressure flushing using inclined plates upstream of orificeNima Najafi0Mehdi Daryaee1Seyed Mahmood Kashefipour2 Department of Water Structures, Faculty of Water and Environmental Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran Department of Water Structures, Faculty of Water and Environmental Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran Department of Water Structures, Faculty of Water and Environmental Engineering, Shahid Chamran University of Ahvaz, Ahvaz, Iran Pressure flushing is a common technique to restore the storage capacity of reservoirs. However, the low quantity of flushed sediment remains a drawback of pressure flushing. Experimentally, the present study used inclined plates upstream of the bottom outlet to increase the flushed sediment in pressure flushing. The variables included the plate width (B), the angel between the vertical line at the outlet center and the normal vector of the inclined plate (α), radial distance of the inclined plates from the orifice center (R), and outlet discharge (Q). The results showed that the flushed sediment significantly enhanced; the quantity of flushed sediment for B = 6.3 cm, α = 60°, R = 8.5 cm, and a Q = 8.34 L/s was 19 times as large as that in the reference test (i.e., without plates). Furthermore, the length, width, and depth of the scour cone in the presence of inclined plates were 3, 2.3, and 3.3 times as high as those in the absence of the inclined plates. Also, equations were developed to predict the volume and dimensions of the scour cone in the presence of inclined plates based on the experimental data. Finally, the importance of the variables was determined using a sensitivity analysis method. Between all considered parameters in this study, the plate distance from the outlet was found to have the highest effect and the plate inclination the lowest effect (three times) in increasing the flushed sediment through the orifice. HIGHLIGHTS Increasing pressure flushing efficiency.; Reducing discharged water volume during pressure flushing operation.; Prevention of sediment deposition close to bottom outlet.;http://ws.iwaponline.com/content/22/10/7701dam reservoirsflushing conepressurized flushing
spellingShingle Nima Najafi
Mehdi Daryaee
Seyed Mahmood Kashefipour
Enhancement of flushed sediment in pressure flushing using inclined plates upstream of orifice
Water Supply
dam reservoirs
flushing cone
pressurized flushing
title Enhancement of flushed sediment in pressure flushing using inclined plates upstream of orifice
title_full Enhancement of flushed sediment in pressure flushing using inclined plates upstream of orifice
title_fullStr Enhancement of flushed sediment in pressure flushing using inclined plates upstream of orifice
title_full_unstemmed Enhancement of flushed sediment in pressure flushing using inclined plates upstream of orifice
title_short Enhancement of flushed sediment in pressure flushing using inclined plates upstream of orifice
title_sort enhancement of flushed sediment in pressure flushing using inclined plates upstream of orifice
topic dam reservoirs
flushing cone
pressurized flushing
url http://ws.iwaponline.com/content/22/10/7701
work_keys_str_mv AT nimanajafi enhancementofflushedsedimentinpressureflushingusinginclinedplatesupstreamoforifice
AT mehdidaryaee enhancementofflushedsedimentinpressureflushingusinginclinedplatesupstreamoforifice
AT seyedmahmoodkashefipour enhancementofflushedsedimentinpressureflushingusinginclinedplatesupstreamoforifice