Browsing by Author "Michelen, Carlos"

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    CACTUS Open Source Code for Hydrokinetic Turbine Design and Analysis: Model Performance Evaluation and Public Dissemination as Open Source Design Tool
    Michelen, Carlos; Murray, Jonathan C.; Neary, Vincent S.; Barone, Mathew (2014-04)
    Sandia National Laboratories recently released an open source code for design and analysis of axial‐flow and cross‐flow marine and hydrokinetic (MHK) turbines, CACTUS (Code for Axial and Cross‐flow TUrbine Simulation), and has initiated an outreach effort to promote its use among MHK researchers and developers. Our aim in this paper is to summarize the recent developments in CACTUS, and present model performance evaluation results that demonstrate CACTUS's potential use as a design and optimization tool for marine hydrokinetic turbines. We present several model validation tests to evaluate the model's ability to predict MHK turbine performance. The results show both the potential use of CACTUS as a design tool and its current limitations. At least two more model validation tests are planned for 2014 as part of this effort: scaled model tests of DOE's Reference Model 1(RM1) and Reference Model 2 (RM2) turbines in 2014 at the University of Minnesota's St. Anthony Falls Laboratory (SAFL).
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    Development and Demonstration of The WEC-Sim Wave Energy Converter Simulation Tool
    Lawson, Michael; Yu, Yi-Hsiang; Ruehl, Kelley; Michelen, Carlos (2014-04)
    The National Renewable Energy Laboratory (NREL) and Sandia National Laboratories (SNL) have developed WEC-Sim to provide the wave energy converter (WEC) design community with an open-source simulation tool. WEC-Sim models the system dynamics of WEC devices using multi- body dynamics methods and simulates hydrodynamic forces using coefficients predicted from potential flow models. In this paper we describe the methodology used in WEC-Sim and demonstrate the use of the code by simulating three WEC devices. Specifically, we model a two- body point absorber and two oscillating surge devices. For each device we describe how the WEC-Sim model was setup and present simulation results, such as predictions of device motions and power production. For verification and validation purposes, results are compared to corresponding results from other modeling tools and experimental data.
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    Model Validation Using Experimental Measurements from the Garfield Thomas Water Tunnel at the Applied Research Laboratory (ARL) at Penn State University
    Gunawan, Budi; Michelen, Carlos; Neary, Vincent S.; Coe, Ryan G.; Johnson, Erik; Fontaine, Arnold; Meyer, Richard S.; Straka, William; Jonson, Michael (2014-04)
    This paper describes the development of a high‐fidelity computational fluid dynamics (CFD) model of a three‐blade horizontal axis current turbine. The CFD model was developed using STAR‐CCM+ and solves the Reynolds‐Averaged Navier‐Stokes (RANS) equation for unsteady flows. Preliminary CFD model results are compared to laboratory measurements. The variables being compared include inflow and wake flow velocity profiles, and performance coefficients (power, thrust and torque coefficients) at different tip‐speed ratios. A preliminary comparison suggests that overall the CFD simulation results have a good agreement with the measurements.