Download or read book Structural and Hydrodynamic Design Optimization Enhancements with Application to Marine Hydrokinetic Turbine Blades written by Matthew G. Trudeau and published by . This book was released on 2011 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling and Simulation of Hydrokinetic Composite Turbine System written by Haifeng Li and published by . This book was released on 2014 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The utilization of kinetic energy from the river is promising as an attractive alternative to other available renewable energy resources. Hydrokinetic turbine systems are advantageous over traditional dam based hydropower systems due to "zero-head" and mobility. The objective of this study is to design and analyze hydrokinetic composite turbine system in operation. Fatigue study and structural optimization of composite turbine blades were conducted. System level performance of the composite hydrokinetic turbine was evaluated. A fully-coupled blade element momentum-finite element method algorithm has been developed to compute the stress response of the turbine blade subjected to hydrodynamic and buoyancy loadings during operation. Loadings on the blade were validated with commercial software simulation results. Reliability-based fatigue life of the designed composite blade was investigated. A particle swarm based structural optimization model was developed to optimize the weight and structural performance of laminated composite hydrokinetic turbine blades. The online iterative optimization process couples the three-dimensional comprehensive finite element model of the blade with real-time particle swarm optimization (PSO). The composite blade after optimization possesses much less weight and better load-carrying capability. Finally, the model developed has been extended to design and evaluate the performance of a three-blade horizontal axis hydrokinetic composite turbine system. Flow behavior around the blade and power/power efficiency of the system was characterized by simulation. Laboratory water tunnel testing was performed and simulation results were validated by experimental findings. The work performed provides a valuable procedure for the design and analysis of hydrokinetic composite turbine systems"--Abstract, page iv.

Download or read book Design Manufacture and Testing of an Open Source Benchmark Composite Hydrokinetic Turbine Blade Preprint written by and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In a trend toward clean energy alternatives, recent years have seen great strides in the marine energy space. Consequently, there is a pressing need for the design, development, and validation of novel energy harvesting technologies such as hydrokinetic devices, which capture kinetic energy from waves, tides, and currents. However, these devices span numerous concepts and designs that often lack solid benchmark research that can be freely referenced throughout their development. This work focuses on the design process of an open-source composite hydrokinetic turbine blade for a three-bladed marine turbine rotor assembly with a diameter of 2.5 m. The proposed blade consists of two structural composite skins that are bonded with an adhesive and filled with a foam core. This study also explores and contrasts the efficiency and resolution of low-fidelity rapid design methodologies and comprehensive high-fidelity approaches in the context of blade design, modeling, and analysis efforts, a key objective in this research. Blade hydrodynamic loads were modeled and applied to finite-element blade models to study deformations and potential failure. Ongoing and upcoming efforts will result in blade manufacture and structural testing at the National Renewable Energy Laboratory. In future work, multiple blades will be deployed at the Living Bridge site at the University of New Hampshire and will be compared to rigid aluminum blades of the same geometry, developed by Sandia National Laboratories. Ultimately, this research will lay foundational groundwork for researchers and manufacturers, establishing a baseline composite blade design that will serve as a benchmark in the development of future hydrokinetic turbine blades.

Download or read book Hydrodynamic Optimization Method and Design Code for Stall regulated Hydrokinetic Turbine Rotors written by Danny Sale and published by . This book was released on 2009 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the adaptation of a wind turbine performance code for use in the development of a general use design code and optimization method for stall-regulated horizontal-axis hydrokinetic turbine rotors. This rotor optimization code couples a modern genetic algorithm and blade-element momentum performance code in a user-friendly graphical user interface (GUI) that allows for rapid and intuitive design of optimal stall-regulated rotors. This optimization method calculates the optimal chord, twist, and hydrofoil distributions which maximize the hydrodynamic efficiency and ensure that the rotor produces an ideal power curve and avoids cavitation. Optimizing a rotor for maximum efficiency does not necessarily create a turbine with the lowest cost of energy, but maximizing the efficiency is an excellent criterion to use as a first pass in the design process. To test the capabilities of this optimization method, two conceptual rotors were designed which successfully met the design objectives.

Download or read book Adaptive Pitch Composite Blades for Axial flow Marine Hydrokinetic Turbines written by Ramona Brockman Barber and published by . This book was released on 2017 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: Marine hydrokinetic (MHK) turbines are quickly becoming a viable and valuable method of generating renewable energy from ocean, tidal, and river currents. Modern MHK turbine blades are typically constructed from fiber reinforced polymer (FRP) composites, which provide superior strength- and stiffness-to-weight ratios and improved fatigue and corrosion resistance compared to traditional metallic alloys. Furthermore, it is possible to hydroelastically tailor the design of an FRP composite blade by manipulating the anisotropic nature of the material, creating a load-dependent adaptive pitch mechanism. With this strategy, the blade geometry is able to passively adjust to the instantaneous inflow, and system performance can be modified over the expected range of operating conditions. Adaptive blade designs have demonstrated the potential to increase performance, reduce hydrodynamic instabilities, and improve structural integrity in aerospace and other marine applications; however, previous research specific to adaptive MHK turbine blades has been preliminary. Further work is needed to better understand and model the behavior of these systems. To that end, the research presented here combines numerical and experimental modeling to develop greater insight into the potential benefits to be gained by the use of adaptive pitch MHK turbine blades. In this work, a well-validated boundary element method-finite element method solver is used to develop a numerical strategy for predicting the performance and structural response of adaptive turbine blades under a wide range of site-specific operating conditions. The behavior of adaptive MHK turbine blades under normal as well as cavitating conditions is analyzed; results suggest numerous advantages possible with the use of adaptive pitch blades. Following the numerical study, an experimental program is outlined in which a flume-scale turbine system is tested under steady and fluctuating inflow conditions. Loading and performance trends found in the experimental study agree well with numerical predictions. Finally, numerical and experimental results are synthesized into a complete analysis of the potential benefits to be gained with the use of adaptive blades in MHK turbine systems. Future research directions are identified with the goal of further evolving adaptive blade technology.

Download or read book Hydrodynamic Optimization and Design of Marine Current Turbines and Propellers written by David Hernán Menéndez Arán and published by . This book was released on 2013 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis addresses the optimization and design of turbine and propeller blades through the use of a lifting line model. An existing turbine optimization methodology has been modified to include viscous terms, non-linear terms, and a hub model. The method is also adapted to the optimization of propellers. Two types of trailing wake geometries are considered: one based on helical wakes which are aligned at the blade (using the so-called "moderately loaded propeller'' assumption), and a second one based on a full wake alignment model in order to represent more accurately the wake geometry and its effect on the efficiency of the rotor. A comparison of the efficiencies and the loading distributions obtained through the present methods is presented, as well as convergence and numerical accuracy studies, and comparisons with existing analytical results. In the case of turbines, various types of constraints are imposed in the optimization method in order to avoid abrupt changes in the designed blade shape. The effect of the constraints on the efficiency of the turbines is studied. Once the optimum loading has been determined, the blade geometry is generated for given chord, thickness and camber distributions. Finally, a low-order potential-based boundary element method and a vortex-lattice method are used to verify the efficiency of the designed turbines.

Download or read book An Evaluation of the U S Department of Energy s Marine and Hydrokinetic Resource Assessments written by National Research Council and published by National Academies Press. This book was released on 2013-04-23 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt: Increasing renewable energy development, both within the United States and abroad, has rekindled interest in the potential for marine and hydrokinetic (MHK) resources to contribute to electricity generation. These resources derive from ocean tides, waves, and currents; temperature gradients in the ocean; and free-flowing rivers and streams. One measure of the interest in the possible use of these resources for electricity generation is the increasing number of permits that have been filed with the Federal Energy Regulatory Commission (FERC). As of December 2012, FERC had issued 4 licenses and 84 preliminary permits, up from virtually zero a decade ago. However, most of these permits are for developments along the Mississippi River, and the actual benefit realized from all MHK resources is extremely small. The first U.S. commercial gridconnected project, a tidal project in Maine with a capacity of less than 1 megawatt (MW), is currently delivering a fraction of that power to the grid and is due to be fully installed in 2013. As part of its assessment of MHK resources, DOE asked the National Research Council (NRC) to provide detailed evaluations. In response, the NRC formed the Committee on Marine Hydrokinetic Energy Technology Assessment. As directed in its statement of task (SOT), the committee first developed an interim report, released in June 2011, which focused on the wave and tidal resource assessments (Appendix B). The current report contains the committee's evaluation of all five of the DOE resource categories as well as the committee's comments on the overall MHK resource assessment process. This summary focuses on the committee's overarching findings and conclusions regarding a conceptual framework for developing the resource assessments, the aggregation of results into a single number, and the consistency across and coordination between the individual resource assessments. Critiques of the individual resource assessment, further discussion of the practical MHK resource base, and overarching conclusions and recommendations are explained in An Evaluation of the U.S. Department of Energy's Marine and Hydrokinetic Resource Assessment.

Download or read book Passive Pitch Control in Marine Hydrokinetic Turbine Blades written by Ramona Brockman Barber and published by . This book was released on 2014 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt: Green and renewable energy technologies are becoming more and more necessary as demand for energy grows exponentially around the world. Recently, there has been increased interest in using marine hydrokinetic turbines to generate energy from ocean currents and tidal flows. The blades of these turbines are slender and are subjected to large, dynamic fluid forces; for that reason they are typically constructed from fiber-reinforced composites. The bend-twist deformation coupling behavior of these materials can be hydroelastically tailored such that the pitch angle of the blades will passively change to adapt to the surrounding flow, creating an instantaneous reaction that can improve system performance over the expected life of the turbine. Potential benefits of this passive control mechanism include increased lifetime power generation, reduced hydrodynamic instabilities, and improved load shedding and structural performance. There are practical concerns, however, that increase the complexity of the design of these bend-twist coupled blades. Large inflow variations in viable locations for turbine implementation combined with system component limitations such as restrictions on the generator and maximum rotational speed require consideration of practical and site-specific constraints. Using a previously validated boundary element method-finite element method solver, this work presents a numerical investigation into the capabilities of passive pitch adaptation under both instantaneous and long-term variable amplitude loading to better describe potential benefits while considering practical design and operational restrictions.

Download or read book Design Optimization of Turbine Blades Using Computational Fluid Dynamics written by Kyle Khem Chand and published by . This book was released on 1997 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Marine hydrokinetic turbine power take off design for optimal performance and low impact on cost of energy written by M. Beam and published by . This book was released on 2013 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Marine Hydrokinetic Turbine Power take off Design for Optimal Performance and Low Impact on Cost of energy written by M. Beam and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Cavitation written by Yves Lecoffre and published by CRC Press. This book was released on 1999-01-01 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text deals with the concept that cavitation is the main limitation to the performance of hydraulic components. Topics covered include the vaporization of liquids due to high velocities or pressure fluctuations, and the effects of cavitation on the performances of rotary machinery. One chapter is devoted to cavitation noise which concerns many users, including surface ships and submarines, and the author finishes with some examples of the use of cavitation and subject-specific measuring techniques.

Download or read book Marine Hydrokinetic Turbine Power take off Design for Optimal Performance and Low Impact on Cost of energy written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aerodynamics of Wind Turbines 2nd edition written by Martin O. L. Hansen and published by Routledge. This book was released on 2013-05-13 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aerodynamics of Wind Turbines is the established essential text for the fundamental solutions to efficient wind turbine design. Now in its second edition, it has been entirely updated and substantially extended to reflect advances in technology, research into rotor aerodynamics and the structural response of the wind turbine structure. Topics covered include increasing mass flow through the turbine, performance at low and high wind speeds, assessment of the extreme conditions under which the turbine will perform and the theory for calculating the lifetime of the turbine. The classical Blade Element Momentum method is also covered, as are eigenmodes and the dynamic behaviour of a turbine. The new material includes a description of the effects of the dynamics and how this can be modelled in an ?aeroelastic code?, which is widely used in the design and verification of modern wind turbines. Further, the description of how to calculate the vibration of the whole construction, as well as the time varying loads, has been substantially updated.

Download or read book Marine Energy Harvesting from Low Cut in Speeds Horizontal Axis Ocean Current Turbine written by Reza Chini and published by . This book was released on 2012 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Structural Optimization of Wind Turbine Blades for Improved Dynamic Performance written by Gerges Edwar Beshay and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The design of the main structure of a wind turbine blade is optimized aiming at the improvement of the overall dynamic performance. Three optimization strategies are developed and tested. The first fundamental one is based on minimizing the total structural mass of the blade spar under frequency and strength constraints. The second and third strategies are concerned with the reduction of the overall vibration level by either minimizing a frequency-placement index or maximizing the natural frequencies and placing them at their target values to avoid large amplitudes and resonance occurrence. Design variables include cross-sectional dimensions and material properties along the spanwise direction of the blade spar. The optimization problem is formulated as a nonlinear constrained problem solved by sequential quadratic programming (SQP) technique. Two specific layup configurations, namely, circumferentially asymmetric stiffness ( CAS ) and circumferentially uniform stiffness ( CUS ), are analyzed. Exact analytical methods are applied to calculate the natural modes of vibration of a composite, thin-walled, tapered blade spar. The influence of coupling on the vibration modes is identified, and the functional behavior of the frequencies with the lamination parameters is thoroughly investigated and discussed. Finite element modeling using NX Nastran solver is performed in order to validate the analytical results. As a case study, optimized blade spar designs of a 750-kW horizontal axis wind turbine are given. The attained solutions show that the approach used in this study enhances the dynamic characteristics of the optimized spar structures as compared with a known baseline design of the wind turbine blade.

Download or read book Hydrokinetic Turbine Composite Blades and Sandwich Structures written by Mokhtar Fal and published by . This book was released on 2020 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Composite materials are gaining interest due to their high strength to weight ratio. This study deals with both experimental and numerical approaches to cover the aspects of the failure of composite materials in hydrokinetic turbine applications. In Part I, the location and magnitude of failure in the horizontal axis water turbine carbon fiber-reinforced polymer (CFRP) composite blades with different laminate stacking sequences were investigated. Two lay-up orientations were adopted for this work ([0°]4 and [0°/90°][sub 2S]). A finite element analysis model was generated to examine the stresses along the blade. Five angles were introduced to study the effect of pitch angle on the CFRP blades. The numerical results showed very good agreement with the experimental results. In Part II, an experimental setup was developed to test the delamination progression in CFRP blades under hydrodynamic loads in a water tunnel. Thermography analysis was employed to scrutinize the propagation of delamination. In addition, a computational fluid dynamics and one-way fluid-structure interaction were developed to predict the stresses along the blade. The unidirectional ([0°]4) blades showed the best performance while the cross-ply blades ([0°/90°][sub 2S]) are prone to delamination. In Part III, the effect of increasing the contact area between the core and facesheet was studied. Two tests (impact and flat-wise tension) were carried out to examine the integrity of the structure. A finite element model was developed to study the damage due to localized load, such as impact load. The results obtained from both the tests (impact and flatwise tension) showed that increasing surface area had improved the structural integrity in regards to damage resistance due to impact, and delamination resistance between the facesheet and the core due to tension"--Abstract, page iv.