Technical Performance and Resource Assessment Projects

Field Measurements at Rivers and Tidal Current Sites for Hydrokinetic Energy Development: Best Practices Manual
This best practices manual provides details on field measurements required at MHK development sites, instrument specifications, and post-processing methods (Neary et al., 2011)
water depth flow velocity vectors
Effects of turbulence on MHK turbine performance

This study at the St. Anthony Falls Laboratory (SAFL) Main Channel has revealed the effects of  large eddy size and shedding frequency on turbine performance and wake flow recovery.  Large energetic eddies shed from in-stream structures, e.g. bridge piers, reduce machine performance, but increase turbulence in the wake and accelerate wake recovery (Neary et al., 2011).
effects of turbulence effects of Turbulence
Synchronized ADV array measurements and data post-processing code

ORNL is leveraging its experience with synchronized ADV array measurements and post-processing in conventional hydropower developed by Dr. Brennan Smith.  This includes synchronized ADV measurements at Verdant’s RITE study site and SAFL’s Main Channel (Gunawan and Neary, 2011). Synchronized measurements will be used to support development and validation of NREL’s TurbSIm model for MHK turbine design.

synchronized ADV array measurements synchronized ADV array measurements synchronized ADV array measurements

Assessment of errors associated with spatial averaging of ADCP measurements and  development of ADCP data post-processing code for MHK applications

ADCP moving-vessel measurement may provide an accurate description of the flow at an MHK site and significantly reduce the measurement cost.  ORNL is assessing the uncertainty of the error magnitude of the spatially-averaged ADCP moving-vessel measurements in a highly controlled laboratory environment and developing an ADCP data post-processing code for MHK applications (Gunawan et al., 2011).

assessment of errors

assessment of errors

 assessment of errors assessment of errors

Model performance evaluation for tidal and ocean current resource assessments

ORNL is currently conducting a detailed performance evaluation of Georgia Tech’s ocean current resource assessment model that will be peer reviewed by the National Academy of Science’s National Research Council’s MHK energy resource assessment committee.  Prior to this, ORNL provided a detailed performance evaluation of Georgia Tech’s tidal current resource assessment model (Stewart and Neary, 2011).

model performance evaluation for tidal and ocean current model performance evaluation for tidal and ocean current

Reference model inflow characterization

ORNL demonstrated that classic semi-theoretical relationships for flat-plate boundary layer shear flows can be used as first order approximations to characterize vertical profiles of mean velocity and turbulence of inflows over the energy extraction plane (EEP) of MHK technologies (Neary, Gunawan and Sale, 2011).
reference model inflow reference model inflow