Water Tank

The water channel is a closed loop open flow flume with a test section made of clear glass to allow visual access from all directions. The test section of the channel is 4 m long with a cross section of 0.6 x 0.6 m. A 20 HP, 3 phase, pump is driving the flow achieving mean velocity of 1 m/s when the test section is fully filled with water. The pump is controlled by a frequency driver, which in turn can be controlled either manually or from the PC. Before entering the test section, the flow passes one honeycomb (25 mm) and 3 consecutive meshes of increasingly finer mesh size (5 mm being the finest), reaching nearly uniform velocity profile at the beginning of the test section. The outflow from the test section is guided through a course mesh to prevent back pressure and standing waves on high flow rates. The channel is equipped with magnetic flow meter connected to the frequency drive; a closed loop control of the pump at preset flow rate is possible. Additional small pump is installed to operate particle and UV filters to maintain water quality in the channel, while each filter can be operated separately. The test section is topped by a set of aluminum profiles on which rails are installed to accommodate a manually driven carriage. Various instruments, such as ADV, hot-films and thermo-couples are mounted on the carriage. Two PC controlled linear stages are utilized for precise positioning of the instruments on vertical and horizontal axis. The adjusten PC equipped with A/D board is used during experiments both to control the water flow and to record instruments. LabView software is being used to operate the facility achieving high level of experiments automation. The channel is used to perform various experimental researches. Currently, modeling air flow above urban canopies and water turbines design parameters researches are of the main focus.