Experimental Study of Particle Clouds in Stagnant Water

Abstract The evolution of single and twin oblique particle clouds in stagnant water was investigated using a series of laboratory experiments and the effects of controlling parameters such as sand mass and nozzle spacing were studied. The time variations of particle cloud properties such as frontal position, horizontal and vertical centroids, cloud width, and frontal velocity were measured using image analysis and Particle Image Velocimetry (PIV) techniques. The entrainment coefficients were extracted from the measurements. It was found that the main vortex motion of the frontal heads altered after the collision and a new integrated frontal head was formed. The effects of release angle and particle interactions were studied by comparing the time histories of maximum centerline velocities. It was found that the centerline velocity of twin oblique particle clouds in comparison with twin vertical particle clouds increased with increasing nozzle spacing. The time history of the ratio of horizontal to vertical centroids in oblique particle clouds determined the potential location of sand particles and a practical model was developed to determine the size and location of particle clouds with time. The time histories of normalized cloud width indicated a significant change after the frontal head collision. The particle interactions due to frontal head collision in twin oblique particle clouds significantly increased the cloud width until particle clouds reached the swarm phase. The time at which twin oblique particle clouds reached the swarm phase was recorded and a linear model was proposed to link the time to reach the swarm phase with the cloud aspect ratio and nozzle spacing.

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Experimental study of sand-water swirling jets in stagnant water

Experiments in Fluids ◽

10.1007/s00348-021-03379-1 ◽

2022 ◽

Vol 63 (1) ◽

Author(s):

Fardin Sharif ◽

Amir Hossein Azimi

Keyword(s):

Experimental Study ◽

Stagnant Water ◽

Swirling Jets

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Experimental study of oblique particle clouds in water

International Journal of Multiphase Flow ◽

10.1016/j.ijmultiphaseflow.2017.01.005 ◽

2017 ◽

Vol 91 ◽

pp. 101-119 ◽

Cited By ~ 5

Author(s):

Mohamad Moghadaripour ◽

Amir Hossein Azimi ◽

Siamak Elyasi

Keyword(s):

Experimental Study ◽

Particle Clouds

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Investigations on the dynamics of particle clouds in stagnant water using response surface methodology

Canadian Journal of Civil Engineering ◽

10.1139/cjce-2016-0379 ◽

2017 ◽

Vol 44 (2) ◽

pp. 117-128 ◽

Cited By ~ 4

Author(s):

Leila Pakzad ◽

Amir H. Azimi

Keyword(s):

Response Surface Methodology ◽

Response Surface ◽

Stagnant Water ◽

Particle Clouds

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Experimental Effect of the Impact of Stagnant Water on Solar Modules

International Journal of Innovative Technology and Exploring Engineering - Special Issue ◽

10.35940/ijitee.c8951.019320 ◽

2020 ◽

Vol 9 (3) ◽

pp. 2095-2100

Keyword(s):

Experimental Study ◽

Power Output ◽

Output Voltage ◽

Operating Temperature ◽

Output Current ◽

Stagnant Water ◽

Pv Module ◽

Pv Modules ◽

Experimental Effect ◽

The Impact

In this research, an experimental study of the impact of stagnant water on solar modules is investigated. Two different experiments using two identical photovoltaic (PV) modules S1 and S2 were used for the study. In the first experiment, the PV module S1 was covered with stagnant water and the second PV module was unshielded with water. In the second experiment, the PV modules were swapped with S2 covered with stagnant water and S1 unshielded with water. The experiments were carried out under normal operating temperature of PV cells at the Department of Electrical Engineering, University of Nigeria, Nsukka on latitude 6:52 degrees north, longitude 7:23 degrees. Results obtained from the first experiment show that the efficiency and power output of S1 PV module decreased by 9.3% and 8.0% respectively when compared with that of S2 PV module. In the case of output voltage and current, it was found that shielding of PV module S1 with stagnant water caused an increase in the output voltage by 1.93% and a decrease in the output current by 10.26%. In the second experiment, the efficiency and Output power of PV module S2 decreased by 9.21% and 8.18% respectively when compared with the unshielded PV module S1. In the case of voltage and current, it was found that shielding of PV module S2 with stagnant water caused an increase in the Output voltage by 1.63% and decrease in the output current by 10.91%.

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