Hydraulic performance of sluice gate with unloaded upstream rotor

Self Cite

Salty groundwater might find its way into dead end legs of a water distribution network and thus efforts are required to clean such parts of the network. This paper reports, for the first time, the results of a visual study for laboratory experimental investigation on the purging process of saline water from a dead-end water pipe using fresh water. Three purging locations and a number of purging flow rates were considered to identify the effect of purging location and purging flow rate on the time required to completely remove saline water from the dead-end pipe. Image processing analysis techniques were used to capture data from the experimental lab setup. A universal gray-intensity to salinity curve was experimentally found to formulate a color intensity to salinity mapping. A script code based on Octave numerical package was written for this regard to determine the temporal variation of the total dissolved salt (TDS) value within the dead leg pipe. It is generally noted that, as Reynolds number gets higher, the time removal ratio (t/ts) gets bigger. It is also noted that, as a purging location gets farther from the dead end, the time required for the complete removal of TDS increases exponentially.

Section: Methodsmentioning

confidence: 99%

Experimental Investigation of Purging Saline Solution from a Dead-End Water Pipe

Elgamal

Farouk

2019

Self Cite

“…Manual tracking involves frame-by-frame analysis using specialized video analysis soft-ware. Automatic tracking can be achieved through general image processing packages like MATLAB/OCTAVE image processing toolbox/package or dedicated video analysis packages developed specifically for object motion tracking, such as Vernier, Tracker, Logger Pro, and others [32][33][34].…”

Section: Video Tracking Packagesmentioning

confidence: 99%

Analysis of Water-Surface Oscillations Upstream of a Double-Right-Angled Bend with Incoming Supercritical Flow

Elgamal,

Chaouachi,

Farouk

et al. 2023

Self Cite

This study deals with the free-surface supercritical flow through a double-right-angled bend (DRAB), which can be found in storm drainage networks in steep terrains. Laboratory experiments showed that strong backwater effects and water-surface oscillations are generated upstream of the DRAB, especially in supercritical flow conditions. This paper investigated the DRAB hydraulic behavior and water-surface heading up (backwater), and oscillations under supercritical flow conditions. Thirty-four lab experiments were conducted with Froude numbers ranging between 1.03 and 2.63. Dye injection and video analysis were used to visually capture the flow structure and to record water-surface oscillations. A tracker package was utilized to analyze the collected visual data. Time series and spectral analysis were used to identify the statistical characteristics of recorded water level time series and the dominant frequencies. It was found that the dominant frequencies of water-surface oscillations upstream of the DRAB range between 1.6 and 4.6 Hz with an average value of about 3 Hz. The Strouhal number of the water-surface oscillations is more sensitive to the Froude number than to the Reynolds number. The Strouhal number ranged between 0.03 and 0.3 for Froude numbers ranging from 2.63 to 1.03. The study confirms that near critical flow conditions exhibit the highest water oscillation, and that the maximum nondimensional water depth upstream of the DRAB is underestimated by both the Grashof formula and Knapp and Ippen (1939) model. A new formula is proposed to estimate the maximum water depth upstream of the DRAB.

“…It can also be conducted directly using the video analysis packages that were specifically developed to track the motion of an object throughout a captured video and have the auto-tracking option. Examples of auto-tracking packages include Vernier, Tracker, Logger Pro, and many others [17,18].…”

Section: Video Tracking Packagesmentioning

confidence: 99%

“…The angular speed of the rotating rotor is one of the parameters that need to be measured. Different approaches can be found in the literature to measure angular speed, including tachometers, stroboscopes, and, more recently, video analysis and tracking [17,18,21].…”

Section: Measurement Of Angular Speedmentioning

confidence: 99%

“…Third, the video analysis technique gives the time-averaged angular speed values and the corresponding temporal perturbations/fluctuations around the time-averaged values. Elgamal et al [18] presented a table that gives guidelines for selecting the required minimum frame per second (fps) rate for the relevant camera to attain a resolution capable of capturing the temporal variations of the angular speed rate.…”

Section: Measurement Of Angular Speedmentioning

confidence: 99%

See 1 more Smart Citation

Drainage of a Water Tank with Pipe Outlet Loaded by a Passive Rotor

Elgamal

Kriaa

Farouk

2021

Self Cite

The optimal design of pipe outlets is an essential objective for many engineering projects. For the first time, this paper reports the results of a laboratory investigation on the effect of using a passive rotor (added at the pipe outlet) on the outlet performance. Different sizes and numbers of blades of rotors were considered. Through the Tracker software package, video and image processing techniques were applied to capture the temporal variations of the tank water depth and the passive rotor’s angular speed. In addition, a normalized average drainage rate (NADR) parameter is defined to quantify the changes in the tank drainage rate as a result of passive rotor utilization. It is noted that adding a 4-bladed symmetric passive rotor will increase NADR by up to 9.0%. The study also shows that the highest increase in NADR is attained when the rotor diameter size is approximately 1.73 times the pipe outlet’s diameter for the case of symmetric 4-blade rotors, and the corresponding average tip rotor speed ratio is 1.65. It is also found that using an asymmetric 3-blade rotor has a negative impact on the NADR due to the significant perturbation produced by the rotor asymmetry.