LDA experiments - flow characterization of the NRC-IOT cavitation and water re-circulation tunnel

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Conference8th Canadian Marine Hydromechanics and Structures Conference, 16-17 October 2007, St. John's, NL
SubjectLDA; LDV; flow velocity; cavitation tank; water tunnel; uncertainty analysis
AbstractFlow characterization experiments were conducted at the NRC-IOT cavitation and water re-circulating tunnel http://iot-ito.nrc-cnrc.gc.ca/. These experiments were part of a task for the 25th ITTC Uncertainty Analysis Committee (http://ittc.sname.org). Flow characteristics of the test section were measured with a two-componment Dantec LDA (Laser Doppler Anemometer) system. The fibre-optic head of the LDA was mounted on a 3-dimensional traversing system. The long term temporal velocity stability at various tunnel velocities was measured at the centerline of the test section over a time period of about 1-- to 120 minutes. The spatial variation across the test section (velocity uniformity) was also measured via LDA profile sweeps. All 3-velocity components wer measure using the LDA head looking from the bottom and from the side windows of the test section. From the bottom window of the test section, the axial and transverse velocity components (x and y velocities) were measured. From the side window, however, the axial and vertical velocity components were measures (x and z velocities). Together, LDA measurements from the bottom and the side windows provide a 3-D volumetric water velocity profile in the test section. The experiments were conducted at the center of the forward window in the test section. Tests for two different water nominal speeds were completed (1.6 m/s & 6.0 m/s, in the test section). These speeds are typical of low and medium tunnel testing speeds. It is aimed that high water speed experiments (> 9 m/s) are to be conducted in future dates. All experiments at the center of the test window were repeated at distances of ±250 mm (?aft? and ?fwd? tests). In this paper, the results of this experimental work are reported. Velocity Temporal Stability (VTS) and Velocity Spatial Uniformity (VSU) results are provided. A comparison between the present NRC-IOT test results and those from much larger cavitation tunnels (in Japan and the US) is provided.
Publication date
AffiliationNRC Institute for Ocean Technology; National Research Council Canada
Peer reviewedNo
NRC number6517
NPARC number8895807
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Record identifier72fbbd67-3848-465e-be2f-89658ec92ea9
Record created2009-04-22
Record modified2016-05-09
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