Experimental investigation of impact of length and height of parallel skimming walls on controlling inlet sediment to lateral intake

2020 ◽  
Vol 20 (3) ◽  
pp. 997-1005
Author(s):  
Sadegh Farshidnia ◽  
Mojtaba Saneie ◽  
Hooman Hajikandi ◽  
Mohammad Rostami
Keyword(s):  
Experimental Investigation ◽  
Dimensional Analysis ◽  
Main Channel ◽  
Rotational Flow ◽  
Sediment Volume ◽  
The Impact

Abstract Parallel skimming walls are regarded as one of most applicable methods for gaining a decline in the amount of sediment entering a lateral intake. The parallel skimming walls are installed on the main channel, in front of the intake span, creating a rotational flow and diverting sediments from the intake span, and as a result a reduction in the amount of sediment entry into the intake can be realized. The present paper aims at experimentally studying the impact of length (L) and height (H) of parallel skimming walls, as well as the effect of discharge shifts associated with the main channel on controlling the inlet sediment into the intake. First, the impact of parallel skimming walls incorporating three lengths (L = 60 cm, 75 cm, 90 cm) in front of the intake is investigated, then the impact of skimming walls incorporating three heights (H = 2 cm, 4 cm, 6 cm) is scrutinized. After each test, the sediment volume entry (V) into the intake was measured. By performing dimensional analysis, dimensionless ratios were obtained and the relation between the variables was determined. The results demonstrated that in the case of parallel skimming walls, the increase in L and H leads to mitigation in the amount of inlet sediment into the intake. Moreover, there is a proper agreement between the procedure of this study and the previous ones.

scholarly journals Experimental Study on the Placement of the Angle and the Distance of Parallel Skimming Walls to Reduce Inlet Sediment in a Lateral Intake

2020 ◽  
Vol 28 (2) ◽  
pp. 23-29
Author(s):  
Sadegh Farshidnia ◽  
Mojtaba Saneie ◽  
Hooman Hajikandi ◽  
Mohammad Rostami
Keyword(s):  
Experimental Study ◽  
Dimensional Analysis ◽  
Main Channel ◽  
The Impact ◽  
Front Section

AbstractParallel skimming walls are regarded as one of the more efficient methods for controlling inlet sediment to a lateral intake. The present study attempts to experimentally scrutinize the impact of the angles of parallel skimming walls (θ), the corresponding distance (b), and the discharge variations of the main channel of the inlet sediment for the control of an intake. First, the impacts of parallel skimming walls incorporating three angles (θ = 0°, 15°, 30°), located in the front section of the intake and the distance between the walls (b=10 cm, 20 cm, 30 cm), were studied. A dimensional analysis showed the dimensionless extraction ratios and the relation between the variables in a laboratory. The results indicate that parallel skimming walls lead to average decreases of 69%, 41% and 26% in the amount of inlet sediment to the intake, for walls with angles of 0°, 15° and 30°, respectively. With regard to the distance between the walls, average decreases of 58%, 70% and 86% were observed for walls with placement distances of b/H=2.5, b/H=5 and b/ H=7.5, respectively.

Experimental Investigation of the Impact of Dual Time Periods on Crash Hazardous Location Identification

ICCTP 2011 ◽  
2011 ◽  
Author(s):  
Gilbert Leano ◽  
Wen Cheng ◽  
Xudong Jia ◽  
Lingqi Kong ◽  
Robert Brennan
Keyword(s):  
Experimental Investigation ◽  
Time Periods ◽  
Location Identification ◽  
The Impact

Maximizing Recall of Gruesome Images for Health Effects Advertising: An Experimental Investigation

2010 ◽  
Vol 16 (4) ◽  
pp. 112-121 ◽  
Author(s):  
Brennen W. Mills ◽  
Owen B. J. Carter ◽  
Robert J. Donovan
Keyword(s):  
Experimental Investigation ◽  
Body Part ◽  
The Body ◽  
Advertising Effectiveness ◽  
Body Parts ◽  
Online Study ◽  
Video Clips ◽  
Video Images ◽  
The Impact

The objective of this case study was to experimentally manipulate the impact on arousal and recall of two characteristics frequently occurring in gruesome depictions of body parts in smoking cessation advertisements: the presence or absence of an external physical insult to the body part depicted; whether or not the image contains a clear figure/ground demarcation. Three hundred participants (46% male, 54% female; mean age 27.3 years, SD = 11.4) participated in a two-stage online study wherein they viewed and responded to a series of gruesome 4-s video images. Seventy-two video clips were created to provide a sample of images across the two conditions: physical insult versus no insult and clear figure/ground demarcation versus merged or no clear figure/ground demarcation. In stage one, participants viewed a randomly ordered series of 36 video clips and rated how “confronting” they considered each to be. Seven days later (stage two), to test recall of each video image, participants viewed all 72 clips and were asked to identify those they had seen previously. Images containing a physical insult were consistently rated more confronting and were remembered more accurately than images with no physical insult. Images with a clear figure/ground demarcation were rated as no more confronting but were consistently recalled with greater accuracy than those with unclear figure/ground demarcation. Makers of gruesome health warning television advertisements should incorporate some form of physical insult and use a clear figure/ground demarcation to maximize image recall and subsequent potential advertising effectiveness.

Experimental investigation of isothermal and reacting flow characteristics downstream of axisymmetric bluff body stabilizers under stratified or fully premixed inlet mixture conditions

2020 ◽  
Author(s):  
Γεώργιος Πατεράκης
Keyword(s):  
Experimental Investigation ◽  
Turbulent Flow ◽  
Bluff Body ◽  
Operating Conditions ◽  
Reacting Flow ◽  
Wide Range ◽  
Flow Features ◽  
Air Mixing ◽  
The Impact ◽  
Stratified Flames

The current work describes an experimental investigation of isothermal and turbulent reacting flow field characteristics downstream of axisymmetric bluff body stabilizers under a variety of inlet mixture conditions. Fully premixed and stratified flames established downstream of this double cavity premixer/burner configuration were measured and assessed under lean and ultra-lean operating conditions. The aim of this thesis was to further comprehend the impact of stratifying the inlet fuelair mixture on the reacting wake characteristics for a range of practical stabilizers under a variety of inlet fuel-air settings. In the first part of this thesis, the isothermal mean and turbulent flow features downstream of a variety of axisymmetric baffles was initially examined. The effect of different shapes, (cone or disk), blockage ratios, (0.23 and 0.48), and rim thicknesses of these baffles was assessed. The variations of the recirculation zones, back flow velocity magnitude, annular jet ejection angles, wake development, entrainment efficiency, as well as several turbulent flow features were obtained, evaluated and appraised. Next, a comparative examination of the counterpart turbulent cold fuel-air mixing performance and characteristics of stratified against fully-premixed operation was performed for a wide range of baffle geometries and inlet mixture conditions. Scalar mixing and entrainment properties were investigated at the exit plane, at the bluff body annular shear layer, at the reattachment region and along the developing wake were investigated. These isothermal studies provided the necessary background information for clarifying the combustion properties and interpreting the trends in the counterpart turbulent reacting fields. Subsequently, for selected bluff bodies, flame structures and behavior for operation with a variety of reacting conditions were demonstrated. The effect of inlet fuel-air mixture settings, fuel type and bluff body geometry on wake development, flame shape, anchoring and structure, temperatures and combustion efficiencies, over lean and close to blow-off conditions, was presented and analyzed. For the obtained measurements infrared radiation, particle image velocimetry, laser doppler velocimetry, chemiluminescence imaging set-ups, together with Fouriertransform infrared spectroscopy, thermocouples and global emission analyzer instrumentation was employed. This helped to delineate a number of factors that affectcold flow fuel-air mixing, flame anchoring topologies, wake structure development and overall burner performance. The presented data will also significantly assist the validation of computational methodologies for combusting flows and the development of turbulence-chemistry interaction models.

Experimental Investigation of the Impact of Cathode Grade on Sludge Formation at the Cathode Block-Aluminum Interface of Hall–Héroult Cells

2018 ◽  
Vol 50 (1) ◽  
pp. 416-428
Author(s):  
Jean-René Landry ◽  
Mojtaba Fallah Fini ◽  
Gervais Soucy ◽  
Martin Désilets ◽  
Patrick Pelletier ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Sludge Formation ◽  
Cathode Block ◽  
The Impact
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