1. The turbine test section was located 15 m downstream of the wave-maker. The wave channel was installed with a piston type wave-maker. By controlling the displacement selleck products and velocity of the wave-maker desired waves of various heights and periods was obtained. The torque generated by

the turbine was measured using a torque meter. Pulley was attached on the runner shaft and via a timing belt the torque was transferred to the torque meter for data logging. The rotational speed (N) of the turbine was measured using a revolution counter attached to the torque meter. A capacitance type wave gauge was installed 3.65 m upstream from the turbine centre. This gage was used to measure the incoming wave properties such as wave height (H) and wave period (T). Another wave gauge was installed in the rear chamber to record the oscillation of the water level in the chamber which was then used to calculate the volume flow rate (Q). Two pressure transducers one each in the front nozzle and rear nozzle check details were attached to measure the pressure and later the reading was

analyzed to obtain the head loss across the turbine (ΔH). The data was handled using a data logger. All the digital signal measurements were logged simultaneously and data acquisition was done at 20 ms intervals. Measurement uncertainties for turbine performance under a loaded condition were estimated to be Q=±1.39%, ΔH=±1.0%, T=±1.4%, PT=±1.5% and η=±2.23% respectively. Here PT and η are turbine power and turbine

efficiency respectively. Three-dimensional modeling was carried out using commercial software, UniGraphics NX 4. Fig. 2 shows Fenbendazole the test model with the turbine. The total length of the augmentation channel was 700 mm. The width of the front guide nozzle, the augmentation channel and the rear chamber was also 700 mm. The augmentation channel consists of front nozzle, rear nozzle and the turbine. Fig. 3 shows the schematic diagram for the augmentation channel and front guide nozzle. The front guide divergence angle, α, was 14° and the front guide nozzle inlet width, WG, was 823 mm. The length, height and width of Numerical Wave-tank (NWT) were 15 m, 1.5 m and 1 m respectively and the height of the rear chamber was 1.5 m. Schematic of the runner of the cross-flow turbine is shown in Fig. 4. There are a total of 30 blades, the length of the runner, L is 700 mm, the outer diameter Do is 260 mm and the inner diameter Di of the runner is 165 mm. The blade entry and exit angles are 30° and 90° respectively. These dimensions are from the actual runner used in the experiments. Computational grid is generated using ANSYS ICEM – CFD. The computational domain is discretized with hexahedral grid. The hexahedral grids are used to ensure that the obtained results are of highest quality that is, high accuracy. The total number of nodes for all the models was 500,000. Fig. 5 shows grid generation for the various parts. The individual components were exported to ANSYS CFX Pre.