Engineering topics

Kilcher, Levi

Publications and source records attributed to Kilcher, Levi.

40 records · Page 3

DOE OSTI2013

TIDAL TURBULENCE SPECTRA FROM A COMPLIANT MOORING

A compliant mooring to collect high frequency turbulence data at a tidal energy site is evaluated in a series of short demon- stration deployments. The Tidal Turbulence Mooring (TTM) improves upon recent bottom-mounted approaches by suspend- ing Acoustic Doppler Velocimeters (ADVs) at mid-water depths (which are more relevant to tidal turbines). The ADV turbulence data are superior to Acoustic Doppler Current Profiler (ADCP) data, but are subject to motion contamination when suspended on a mooring in strong currents. In this demonstration, passive stabilization is shown to be sufficient for acquiring bulk statistics of the turbulence, without motion correction. With motion cor- rection (post-processing), data quality is further improved; the relative merits of direct and spectral motion correction are dis- cussed.

ADCP↗

DOE OSTI2013

Tidal Energy Site Characterization East Forelands Alaska

During the summer field season in 2012, Benthic GeoScience Inc. (Benthic) mobilized under contract with Ocean Renewable Power Company (ORPC) in order to conduct precise geospatial measurements of the seafloor accomplishing a preliminary Site Characterization Study for the ORPC East Forelands Tidal Energy Power Project. This study included a high-density bathymetric survey, acoustic reflective intensity imagery, and an assessment of the physical character of the ORPC East Forelands Tidal Energy Power Project environment. The Multibeam Echosounder (MBES) survey included a large area surrounding the East Forelands of Cook Inlet in the vicinity of Nikiski, Alaska. Included in this submission are the report for the East Forelands Site Characterization Study and the accompanying data from the survey as described below. The digital deliverables from this effort include: - Comprehensive Site Characterization Report (Format: PDF, Ver. 1.1, March 2013) - Comprehensive 3D Fledermaus Presentation (Format: SCENE, Ver. 1.1, March 2013) - Bathymetric Surface (Format: ASCVer. 1, March 2013) - Slope Gradient Surface (Format: ASCVer. 1, March 2013) - Comprehensive Acoustic Intensity Image (Format: TIF/TWFVer. 1, March 2013) - Geologic Seafloor Interpretation Surface (Format: ASCVer. 1.0, March 2013) - Comprehensive Google Earth Presentation (Format: KMZVer. 1.1, March 2013)

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DOE OSTI2012

Admiralty Inlet Hub-Height Turbulence Measurements from June 2012

This data is from measurements at Admiralty Head, in Admiralty Inlet. The measurements were made using an IMU equipped ADV mounted on a mooring, the 'Tidal Turbulence Mooring' or 'TTM'. The inertial measurements from the IMU allows for removal of mooring motion in post processing. The mooring motion has been removed from the stream-wise and vertical velocity signals (u, w). The lateral (v) velocity may have some 'persistent motion contamination' due to mooring sway. The ADV was positioned 11m above the seafloor in 58m of water at 48.1515N, 122.6858W. Units ------ - Velocity data (_u, urot, uacc) is in m/s. - Acceleration (Accel) data is in m/s^2. - Angular rate (AngRt) data is in rad/s. - The components of all vectors are in 'ENU' orientation. That is, the first index is True East, the second is True North, and the third is Up (vertical). - All other quantities are in the units defined in the Nortek Manual. Motion correction and rotation into the ENU earth reference frame was performed using the Python-based open source DOLfYN library (linked in resources). Details on motion correction can be found there. For additional details on this dataset see the included Marine Energy Technology Symposium paper.

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DOE OSTI2011

Admiralty Inlet Advanced Turbulence Measurements: Final Data and Code Archive

Data and code that is not already in a public location that is used in Kilcher, Thomson, Harding, and Nylund (2017) "Turbulence Measurements from Compliant Moorings - Part II: Motion Correction" doi: 10.1175/JTECH-D-16-0213.1. The links point to Python source code used in the publication. All other files are source data used in the publication.

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