Masoud Sajedi Sabegh; Mojtaba Saneie; Hosseinali Abdul Hai; Shahram Behmanesh; Abbas Matinfar
Abstract
Aquaculture cylindrical tanks are growing in the world due to the less water consumption and more product efficiency. Study on Hydraulic of this tank is the first step for recognition of sedimentation and solid removal efficiency. This paper is a laboratory study based on flow velocity analysis in different ...
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Aquaculture cylindrical tanks are growing in the world due to the less water consumption and more product efficiency. Study on Hydraulic of this tank is the first step for recognition of sedimentation and solid removal efficiency. This paper is a laboratory study based on flow velocity analysis in different flow depth. The results show that the flow velocity gradient increased in the vector of inlet current toward tank inner bank and due to the incoherence of ISO-velocity layers in different depth, the secondary currents shaped particularly near the tank bank. Also, related to jet current forces, reflected current formed in different parts of the tank pyramid by incidence of jet current to bank of the tank. Local velocity in the middle and beneath depth increased and reflected current depreciate in longer distance on circular current. By increasing the outlet central discharge, the current velocity increased in deeper depth. Due to the local and secondary flows, there is not a match velocity pattern for different discharges in tank. Range of ratio of local velocity to average velocity with depth of 0.2 from tank bottom changes between 0.6 and 1.78 for inlet discharges. Also the results show that the calculated Froude number in each local point related to ratio of local radius to tank radius.
Masoud Sajedi Sabegh; Mojtaba Saneie; Mehdi Habibi; Ali Akbar Abbasi; Mehdi Ghadimkhani
Volume 2, Issue 4 , January 2011, , Pages 206-210
Abstract
In this paper the effect of tree planting in a river bank on the shear velocity of flow was studied in a laboratory environment. At first a physical model was established in a 1.5m wide, 30m long experimental flume with a longitudinal slope of 0.01. Then a number of bars with 6.5mm in diameter, ...
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In this paper the effect of tree planting in a river bank on the shear velocity of flow was studied in a laboratory environment. At first a physical model was established in a 1.5m wide, 30m long experimental flume with a longitudinal slope of 0.01. Then a number of bars with 6.5mm in diameter, stimulated as trees, were located on the bank surface with a slope of 1:3 in two different orientations (square and triangular forms), three different heights (5, 6.5 and 8cm), and three different intensities (6*6/6*3, 8*8/8*4, 10*10/10*5). After that, the flow hydraulic parameters (such as discharge, water level and velocity) and their variation versus the change in experimentally planted trees were measured and analyzed. At least 19 series of laboratory tests with 5 different discharges were implemented. The results showed that, there is a relationship between planted tree and shear velocity. Also relationship between shear Reynolds () and the average velocity to shear velocity ratio () showed that vegetation could increase the roughness coefficient also by increasing the tree density, the ratio of and the roughness are increased. The roughness coefficient in all cases of not using vegetation, tree planted in square form and tree planted in triangular form, was increased respectively.
