Four Tidal Energy Research Projects Funded
The Offshore Energy Research Association of Nova Scotia (OERA) has recently funded four (4) tidal energy research projects under their Open Call Program. OERA awards a maximum of $20,000 on its various Open Call Projects, where such funds are leveraged with financial support from others to cover the total project costs. The following are the most recent winners:
"Measuring the acoustic detection range of large whales using an autonomous underwater (Slocum) ocean glider to improve an acoustic whale alert system for use by the offshore marine industry in Atlantic Canada"
Lead Proponent: Dalhousie University Department of Oceanography - Dr. Chris Taggart and Mr. Hansen Johnson, PhD candidate
The proposed research is to investigate a novel (and in-development) passive acoustic monitoring (PAM) system for use in detecting marine mammals. The work builds on a current research initiative between Dalhousie University and Woods Hole Oceanographic Institute (WHOI) MA, USA.
The Dalhousie researchers are pioneering a system that combines autonomous underwater ocean gliders (Slocum gliders) with the specialized WHOI- PAM system with utility to detect, classify, and report whale calls back to shore at intervals of ~ two hours.
One of the limitations of the ‘PAM-glider’ system, however, is the uncertainty in whale detection range relative to the glider. Determining detection range uncertainty is essential to effectively use the PAM system to monitor for the presence and location of whales. A system that incorporates sound-range uncertainty will provide an improved estimate of the area wherein the detected whale call most likely originated. The primary objective for this research is to evaluate the range-dependent accuracy of the glider-based PAM detection system.
This information will be used to support the planned PAM-glider deployment scheduled for spring 2017 off Cape Cod, MA, in collaboration with WHOI and Dalhousie. Analytics from this US based deployment will be critical to informing future glider-based system development here in Atlantic Canada.
The project completion date is scheduled for 31 March 2018.
"Finite Element Analysis to assess fish mortality from interactions with tidal turbine blades"
Lead Proponent: Blumara Corp - Mr. Nicholas Fyffe
The project objective is to use a computer modeling technique known as finite element analysis (FEA) to simulate the impact of a tidal turbine blade on fish and to assess whether mortality of marine life can be expected in such an event. Similar FEA research has been conducted in other sectors, such as bird strikes on aircraft, marine mammal-turbine strikes, and fish-hydro turbine blade interactions. The proponent will apply similar FEA modeling techniques for this project. The project objectives are to: 1) assess whether FEA can be used to simulate turbine blade impacts with fish and other marine life; 2) provide an indication whether turbine blades are likely to result in fish mortality; and 3) to assess the viability of strain gauges as an effective way to monitor fish-blade collisions.
The primary research activities are to run several FEA simulations (different flow speeds and turbine operational conditions) and analyse the data to profile the forces, stresses and strains potential on marine life if struck by a turbine blade. In addition, a laboratory or field test* will be conducted using strain gauges, to calibrate and validate the FEA model. The simulation and field results will be correlated.
The outcomes of this research will be the development of a methodology and prediction tool for use in assessing the likelihood of mortality for fish-turbine interactions.
Blumara Corp will be working with Nova Scotia Community College to complete the work, with a project completion date set for late March 2018.
* Noted that no live fish will be harmed or killed from this work.
"Real-time particle acceleration/particle velocity (PA/PV) measurement system evaluation in a tidal environment"
Lead Proponent: Jasco Applied Sciences - Mr. John Moloney
Lead Proponent: CulOcean Consulting - Dr. Joel Culina
This project is a test/trial of a near-real-time, drifting acoustic measurement system which will feature a particle acceleration/particle velocity (PA/PV) measurement sensor (vector sensor).
This experiment will evaluate the performance of the PA/PV system in a high flow environment. The work will lead to a better understanding of the effects of flow on the PA/PV system and its utility across the broad spectrum of environmental acoustics. The system couples a ‘M20’ vector sensor with patented JASCO electronics for deployment testing in the Minas Passage. The M20 is a novel sensor that measures water particle velocity and accelerations instead of pressure waves like a hydrophone. The PA/PV system holds promise as a technology to provide more sensitive and accurate acoustic measurements over traditional hydrophones. The trial will also demonstrate the delivery of acoustic measurement data via the internet in near real-time. The PA/PV sensor is a directional system which should offer some indication of the direction (bearing) of acoustic noise sources.
With success, this sensor will help improve the detection of marine mammals to better understand the critical periods related to marine mammal habitat usage and more accurately measure underwater noise – especially in tidal energy sites.
"Wake Characterization of an operational tidal turbine"
Wakes arise downstream of immersed or partially immersed obstacles including islands, seabed forms, and turbines.The spatial footprint of a turbine is not dominated by the turbine itself, rather by its wake and the associated velocity deficits and increased turbulence.Turbine wakes represent a critical constraint on turbine placement.In the context of an environment assessment, there is a clear need to properly characterize turbine wake and its near field impact on the flow regime.
The project objective is to use different tools and techniques to improve understanding of wake behaviour, for use by industry in optimizing turbine placements.As a first step, the project team will collect observations of the velocity deficit behind the Cape Sharp turbine deployed in the Crown Lease Area (CLA) in the Bay of Fundy, using vessel-mounted and bottom-mounted acoustic Doppler current profilers (ADCPs). These observations will be used to validate a CFD model of the Cape Sharp turbine and CLA waters.This model will provide the industry at large with a powerful tool for array planning.
Dr. Culina will be collaborating with FORCE and Envenio (New Brunswick) to complete the project.
The scheduled completion date is 31 March 2018.
For more information on any of these projects or our funding calls, please visit our website at www.oera.ca