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Dr. M. Sergio Campobasso
Renewable Energy and Computational Fluid Dynamics, Lancaster University, LA1 4YR Lancaster, UK

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Research Keywords & Expertise

0 Offshore Renewable Energy
0 high-performance computing
0 Applied machine learning
0 Distributed wind energy generation
0 Wind and tidal current turbine fluid mechanics

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high-performance computing
Floating offshore wind
Blade erosion and maintenance planning
Turbulence modelling
Horizontal and Vertical Axis Turbines
Oscillating wings for power generation

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Journal article
Published: 31 July 2021 in Energy Conversion and Management
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Blade leading edge erosion is acknowledged to significantly reduce the energy yield of wind turbines. The problem is particularly severe for offshore installations, due to faster erosion progression boosted by harsh environmental conditions. This study presents and demonstrates an experimentally validated simulation-based technology for rapidly and accurately estimating wind turbine energy yield losses due to general leading edge erosion. The technology combines the predictive accuracy of two- and three-dimensional Navier–Stokes computational fluid dynamics with the runtime reductions enabled by artificial neural networks and wind turbine engineering codes using the blade element momentum theory. The main demonstration is based on the assessment of the annual energy yield of the National Renewable Energy Laboratory 5 MW reference turbine affected by leading edge erosion damage of increasing severity, considering damages based on available laser scans and previous leading edge erosion analysis. Results also include sensitivity studies of the energy loss to the wind characteristics of the installation site. It is found that the annual energy loss varies between about 0.3 and 4%, depending on the damage severity and the site wind characteristics. The study also illustrates the necessity of resolving the geometry of eroded leading edges rather than accounting for the effects of erosion with surrogate models, since, after an initial increase of distributed surface roughness, erosion yields leading edge geometry alterations causing aerodynamic losses exceeding those due to the loss of boundary layer laminarity consequent to roughness-induced transition. The presented technology enables estimating in a few minutes the amount of energy lost to erosion for many-turbine wind farms, and offers a key tool for predictive maintenance.

ACS Style

Lorenzo Cappugi; Alessio Castorrini; Aldo Bonfiglioli; Edmondo Minisci; M. Sergio Campobasso. Machine learning-enabled prediction of wind turbine energy yield losses due to general blade leading edge erosion. Energy Conversion and Management 2021, 245, 114567 .

AMA Style

Lorenzo Cappugi, Alessio Castorrini, Aldo Bonfiglioli, Edmondo Minisci, M. Sergio Campobasso. Machine learning-enabled prediction of wind turbine energy yield losses due to general blade leading edge erosion. Energy Conversion and Management. 2021; 245 ():114567.

Chicago/Turabian Style

Lorenzo Cappugi; Alessio Castorrini; Aldo Bonfiglioli; Edmondo Minisci; M. Sergio Campobasso. 2021. "Machine learning-enabled prediction of wind turbine energy yield losses due to general blade leading edge erosion." Energy Conversion and Management 245, no. : 114567.

Preprint content
Published: 16 July 2021
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ACS Style

Andrea Ortolani; Giacomo Persico; Jernej Drofelnik; Adrian Jackson; Michele Sergio Campobasso. High-Fidelity Calculation of Floating Offshore Wind Turbines Under Pitching Motion. 2021, 1 .

AMA Style

Andrea Ortolani, Giacomo Persico, Jernej Drofelnik, Adrian Jackson, Michele Sergio Campobasso. High-Fidelity Calculation of Floating Offshore Wind Turbines Under Pitching Motion. . 2021; ():1.

Chicago/Turabian Style

Andrea Ortolani; Giacomo Persico; Jernej Drofelnik; Adrian Jackson; Michele Sergio Campobasso. 2021. "High-Fidelity Calculation of Floating Offshore Wind Turbines Under Pitching Motion." , no. : 1.

Research article
Published: 27 June 2021 in Wind Energy
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Wind turbine blade leading edge erosion reduces the lift and increases the drag of the blade airfoils. This occurrence, in turn, reduces turbine power and energy yield. This study focuses on the aerodynamic analysis of large and sparse erosion cavities, observed in intermediate to advanced erosion stages, whose size and surface pattern do not lend themselves to experimental and numerical analysis by means of distributed roughness models alone. Making use of three-dimensional Navier-Stokes computational fluid dynamics enhanced by laminar-to-turbulent transition modeling, and geometrically resolving individual erosion cavities, the study validates this simulation-based approach for predicting the aerodynamics and performance loss of blade sections featuring the aforementioned erosion cavities against available experimental data. It is found that the considered cavities can trigger transition, indicating the necessity of both resolving their geometry in the simulations and also modeling distributed surface roughness, of typically lower level, as this latter affects the properties of boundary layers and, if sufficiently high, may trigger transition over the entire spanwise length affected. The energy yield loss of a utility-scale turbine due to the considered erosion pattern is found to be between 2.1% and 2.6% using measured and computed force data of the nominal and eroded outboard blade airfoil. A parametric analysis of the cavity geometry suggests that the geometry of the cavity edge has a much larger impact on aerodynamic performance than the cavity depth.

ACS Style

Michele Sergio Campobasso; Alessio Castorrini; Lorenzo Cappugi; Aldo Bonfiglioli. Experimentally validated three‐dimensional computational aerodynamics of wind turbine blade sections featuring leading edge erosion cavities. Wind Energy 2021, 1 .

AMA Style

Michele Sergio Campobasso, Alessio Castorrini, Lorenzo Cappugi, Aldo Bonfiglioli. Experimentally validated three‐dimensional computational aerodynamics of wind turbine blade sections featuring leading edge erosion cavities. Wind Energy. 2021; ():1.

Chicago/Turabian Style

Michele Sergio Campobasso; Alessio Castorrini; Lorenzo Cappugi; Aldo Bonfiglioli. 2021. "Experimentally validated three‐dimensional computational aerodynamics of wind turbine blade sections featuring leading edge erosion cavities." Wind Energy , no. : 1.

Journal article
Published: 18 November 2020 in Journal of Engineering for Gas Turbines and Power
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The unsteady aerodynamics of floating wind turbines is more complex than that of fixed-bottom turbines, and the uncertainty of low-fidelity predictions is higher for floating turbines. Navier–Stokes computational fluid dynamics (CFD) can improve the understanding of rotor and wake aerodynamics of floating turbines, and help improving lower-fidelity models. Here, the flow field of the NREL 5 MW rotor with fixed tower, and subjected to prescribed harmonic pitching past the tower base are investigated using blade-resolved CFD compressible flow COSA simulations and incompressible flow FLUENT simulations. CFD results are also compared to predictions of the FAST wind turbine code, which uses blade element momentum theory (BEMT). The selected rotor pitching parameters correspond to an extreme regime unlikely to occur without faults of the turbine safety system, and thus relevant to extreme aerodynamic load analysis. The rotor power and loads in fixed-tower mode predicted by both CFD codes and BEMT are in very good agreement. For the floating turbine, all predicted periodic profiles of rotor power and thrust are qualitatively similar, but the power peaks of both CFD predictions are significantly higher than those of BEMT. Moreover, cross-comparisons of the COSA and FLUENT predictions of blade static pressure also highlight significant compressible flow effects on rotor power and loads. The CFD analyses of the downstream rotor flow also reveal wake features unique to pitching turbines, primarily the space- and time-dependence of the wake generation strength, highlighted by intermittency of the tip vortex shedding.

ACS Style

Andrea Ortolani; Giacomo Persico; Jernej Drofelnik; Adrian Jackson; Michele Sergio Campobasso. Computational Fluid Dynamics Analysis of Floating Offshore Wind Turbines in Severe Pitching Conditions. Journal of Engineering for Gas Turbines and Power 2020, 142, 1 .

AMA Style

Andrea Ortolani, Giacomo Persico, Jernej Drofelnik, Adrian Jackson, Michele Sergio Campobasso. Computational Fluid Dynamics Analysis of Floating Offshore Wind Turbines in Severe Pitching Conditions. Journal of Engineering for Gas Turbines and Power. 2020; 142 (12):1.

Chicago/Turabian Style

Andrea Ortolani; Giacomo Persico; Jernej Drofelnik; Adrian Jackson; Michele Sergio Campobasso. 2020. "Computational Fluid Dynamics Analysis of Floating Offshore Wind Turbines in Severe Pitching Conditions." Journal of Engineering for Gas Turbines and Power 142, no. 12: 1.

Journal article
Published: 22 October 2020 in Sustainability
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Tidal stream turbines fixed on the seabed can harness the power of tides at locations where the bathymetry and/or coastal geography result in high kinetic energy levels of the flood and/or neap currents. In large turbine arrays, however, avoiding interactions between upstream turbine wakes and downstream turbine rotors may be hard or impossible, and, therefore, tidal array layouts have to be designed to minimize the power losses caused by these interactions. For the first time, using Navier-Stokes computational fluid dynamics simulations which model the turbines with generalized actuator disks, two sets of flume tank experiments of an isolated turbine and arrays of up to four turbines are analyzed in a thorough and comprehensive fashion to investigate these interactions and the power losses they induce. Very good agreement of simulations and experiments is found in most cases. The key novel finding of this study is the evidence that the flow acceleration between the wakes of two adjacent turbines can be exploited not only to increase the kinetic energy available to a turbine working further downstream in the accelerated flow corridor, but also to reduce the power losses of said turbine due to its rotor interaction with the wake produced by a fourth turbine further upstream. By making use of periodic array simulations, it is also found that there exists an optimal lateral spacing of the two adjacent turbines, which maximizes the power of the downstream turbine with respect to when the two adjacent turbines are absent or further apart. This is accomplished by trading off the amount of flow acceleration between the wakes of the lateral turbines, and the losses due to shear and mixing of the front turbine wake and the wakes of the two lateral turbines.

ACS Style

Federico Attene; Francesco Balduzzi; Alessandro Bianchini; M. Sergio Campobasso. Using Experimentally Validated Navier-Stokes CFD to Minimize Tidal Stream Turbine Power Losses Due to Wake/Turbine Interactions. Sustainability 2020, 12, 8768 .

AMA Style

Federico Attene, Francesco Balduzzi, Alessandro Bianchini, M. Sergio Campobasso. Using Experimentally Validated Navier-Stokes CFD to Minimize Tidal Stream Turbine Power Losses Due to Wake/Turbine Interactions. Sustainability. 2020; 12 (21):8768.

Chicago/Turabian Style

Federico Attene; Francesco Balduzzi; Alessandro Bianchini; M. Sergio Campobasso. 2020. "Using Experimentally Validated Navier-Stokes CFD to Minimize Tidal Stream Turbine Power Losses Due to Wake/Turbine Interactions." Sustainability 12, no. 21: 8768.

Journal article
Published: 22 July 2020 in International Journal of Heat and Fluid Flow
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This study focusses on the fluid mechanic analysis and performance assessment of a one-phase swirling flow multi-nozzle annular jet pump using Reynolds-averaged Navier–Stokes simulations and experimental measurements carried out with a bespoke test rig. The numerical investigation of the flow physics of the device, key to understanding its fluid dynamics and optimising its performance, is made particularly challenging by the existence of flow swirl. Thus, the predictive capabilities of two alternative approaches for the turbulence closure of the Reynolds-averaged Navier–Stokes equations, namely the k-ω shear stress transport and the Reynolds stress models, are assessed against measured static pressure fields for three regimes characterised by different swirl strength, and a thorough cross-comparative analysis of the flow physics using the two closures is performed to complement the information provided by the experimental measurements. At the lowest swirl level, the two simulation types are in very good agreement, and they both agree very well with the measured static pressure fields. As the flow swirl increases, the two numerical results differ more and the Reynolds stress model is in better agreement with the measured static pressure. At the highest swirl level the shear stress transport analysis predicts weaker dissipation of the jet energy and stronger mixing of injected and pumped streams, resulting in higher performance predictions than obtained with the Reynolds stress model. A CFD-based sensitivity analysis also highlights the impact of nozzle diameter and flow swirl on the pump performance, proving new guidelines for the design optimisation of this pump.

ACS Style

A. Morrall; S. Quayle; M.S. Campobasso. Turbulence modelling for RANS CFD analyses of multi-nozzle annular jet pump swirling flows. International Journal of Heat and Fluid Flow 2020, 85, 108652 .

AMA Style

A. Morrall, S. Quayle, M.S. Campobasso. Turbulence modelling for RANS CFD analyses of multi-nozzle annular jet pump swirling flows. International Journal of Heat and Fluid Flow. 2020; 85 ():108652.

Chicago/Turabian Style

A. Morrall; S. Quayle; M.S. Campobasso. 2020. "Turbulence modelling for RANS CFD analyses of multi-nozzle annular jet pump swirling flows." International Journal of Heat and Fluid Flow 85, no. : 108652.

Journal article
Published: 26 June 2020 in Journal of Turbomachinery
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Estimating reliably and rapidly the losses of wind turbine annual energy production due to blade surface damage is essential for optimizing maintenance planning and, in the case of leading edge erosion, assessing the need for protective coatings. These requirements prompted the development of the prototype system presented herein, using machine learning, wind turbine engineering codes, and computational fluid dynamics to estimate annual energy production losses due to blade leading edge delamination. The power curve of a turbine with nominal and damaged blade surfaces is determined, respectively, with the open-source FAST and AeroDyn codes of the National Renewable Energy Laboratory, both using the blade element momentum theory for turbine aerodynamics. The loss prediction system is designed to map a given three-dimensional geometry of a damaged blade onto a damaged airfoil database, which, in this study, features 6000+ airfoil geometries, each analyzed with Navier–Stokes computational fluid dynamics over the working range of angles of attack. To avoid lengthy aerodynamic analyses to assess losses due to damages monitored during turbine operation, the airfoil force data of a damaged turbine required by AeroDyn are rapidly obtained using a machine learning method trained using the pre-existing airfoil database. Presented results demonstrate that realistic estimates of the annual energy production loss of a utility-scale offshore turbine due to leading edge delamination are obtained in just a few seconds using a standard desktop computer. This highlights viability and industrial impact of this new technology for managing wind farm energy losses due to blade erosion.

ACS Style

Michele Sergio Campobasso; Anna Cavazzini; Edmondo Minisci. Rapid Estimate of Wind Turbine Energy Loss Due to Blade Leading Edge Delamination Using Artificial Neural Networks. Journal of Turbomachinery 2020, 142, 1 -23.

AMA Style

Michele Sergio Campobasso, Anna Cavazzini, Edmondo Minisci. Rapid Estimate of Wind Turbine Energy Loss Due to Blade Leading Edge Delamination Using Artificial Neural Networks. Journal of Turbomachinery. 2020; 142 (7):1-23.

Chicago/Turabian Style

Michele Sergio Campobasso; Anna Cavazzini; Edmondo Minisci. 2020. "Rapid Estimate of Wind Turbine Energy Loss Due to Blade Leading Edge Delamination Using Artificial Neural Networks." Journal of Turbomachinery 142, no. 7: 1-23.

Conference paper
Published: 03 November 2019 in ASME 2019 2nd International Offshore Wind Technical Conference
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Estimating reliably and rapidly the losses of wind turbine annual energy production due to blade surface damage is essential for optimizing maintenance planning and, in the frequent case of leading edge erosion, assessing the need for protective coatings. These requirements prompted the development of the prototype system presented herein, using machine learning, wind turbine engineering codes and computational fluid dynamics to estimate wind turbine annual energy production losses due to blade leading edge damage. The power curve of a turbine with nominal or damaged blade surfaces is determined respectively with the open-source FAST and AeroDyn codes of the National Renewable Energy Laboratory, both using the blade element momentum theory for turbine aerodynamics. The loss prediction system is designed to map a given three-dimensional geometry of a damaged blade onto a damaged airfoil database, which, in this study, consists of 2700+ airfoil geometries, each analyzed with Navier-Stokes computational fluid dynamics over the working range of angles of attack. To avoid the need for lengthy aerodynamic analyses to assess losses due to damages monitored during turbine operation, the airfoil force data of a damaged turbine required by AeroDyn are rapidly obtained using a machine learning method trained using the pre-existing airfoil database. Presented results focus on the analysis of a utility-scale offshore wind turbine and demonstrate that realistic estimates of the annual energy production loss due to leading edge surface damage can be obtained in just a few seconds using a standard desktop computer, highlighting the viability and the industrial impact of this new technology for wind farm energy losses due to blade erosion.

ACS Style

Anna Cavazzini; Edmondo Minisci; Michele Sergio Campobasso. Machine Learning-Aided Assessment of Wind Turbine Energy Losses due to Blade Leading Edge Damage. ASME 2019 2nd International Offshore Wind Technical Conference 2019, 1 .

AMA Style

Anna Cavazzini, Edmondo Minisci, Michele Sergio Campobasso. Machine Learning-Aided Assessment of Wind Turbine Energy Losses due to Blade Leading Edge Damage. ASME 2019 2nd International Offshore Wind Technical Conference. 2019; ():1.

Chicago/Turabian Style

Anna Cavazzini; Edmondo Minisci; Michele Sergio Campobasso. 2019. "Machine Learning-Aided Assessment of Wind Turbine Energy Losses due to Blade Leading Edge Damage." ASME 2019 2nd International Offshore Wind Technical Conference , no. : 1.

Journal article
Published: 24 September 2019 in Journal of Engineering for Gas Turbines and Power
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This study provides a novel contribution toward the establishment of a new high-fidelity simulation-based design methodology for stall-regulated horizontal axis wind turbines. The aerodynamic design of these machines is complex, due to the difficulty of reliably predicting stall onset and poststall characteristics. Low-fidelity design methods, widely used in industry, are computationally efficient, but are often affected by significant uncertainty. Conversely, Navier–Stokes computational fluid dynamics (CFD) can reduce such uncertainty, resulting in lower development costs by reducing the need of field testing of designs not fit for purpose. Here, the compressible CFD research code COSA is used to assess the performance of two alternative designs of a 13-m stall-regulated rotor over a wide range of operating conditions. Validation of the numerical methodology is based on thorough comparisons of novel simulations and measured data of the National Renewable Energy Laboratory (NREL) phase VI turbine rotor, and one of the two industrial rotor designs. An excellent agreement is found in all cases. All simulations of the two industrial rotors are time-dependent, to capture the unsteadiness associated with stall which occurs at most wind speeds. The two designs are cross-compared, with emphasis on the different stall patterns resulting from particular design choices. The key novelty of this work is the CFD-based assessment of the correlation among turbine power, blade aerodynamics, and blade design variables (airfoil geometry, blade planform, and twist) over most operational wind speeds.

ACS Style

Andrea Giuseppe Sanvito; Giacomo Persico; Michele Sergio Campobasso. Assessing the Sensitivity of Stall-Regulated Wind Turbine Power to Blade Design Using High-Fidelity Computational Fluid Dynamics. Journal of Engineering for Gas Turbines and Power 2019, 141, 1 .

AMA Style

Andrea Giuseppe Sanvito, Giacomo Persico, Michele Sergio Campobasso. Assessing the Sensitivity of Stall-Regulated Wind Turbine Power to Blade Design Using High-Fidelity Computational Fluid Dynamics. Journal of Engineering for Gas Turbines and Power. 2019; 141 (10):1.

Chicago/Turabian Style

Andrea Giuseppe Sanvito; Giacomo Persico; Michele Sergio Campobasso. 2019. "Assessing the Sensitivity of Stall-Regulated Wind Turbine Power to Blade Design Using High-Fidelity Computational Fluid Dynamics." Journal of Engineering for Gas Turbines and Power 141, no. 10: 1.

Conference paper
Published: 17 June 2019 in Volume 9: Oil and Gas Applications; Supercritical CO2 Power Cycles; Wind Energy
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This study provides a novel contribution towards the establishment of a new high–fidelity simulation–based design methodology for stall–regulated horizontal axis wind turbines. The aerodynamic design of these machines is complex, due to the difficulty of reliably predicting stall onset and post–stall characteristics. Low–fidelity design methods, widely used in industry, are computationally efficient, but are often affected by significant uncertainty. Conversely, Navier–Stokes CFD can reduce such uncertainty, resulting in lower development costs by reducing the need of field testing of designs not fit for purpose. Here, the compressible CFD research code COSA is used to assess the performance of two alternative designs of a 13–meter stall–regulated rotor over a wide range of operating conditions. Validation of the numerical methodology is based on thorough comparisons of novel simulations and measured data of the NREL Phase VI turbine rotor, and one of the two industrial rotor designs. An excellent agreement is found in all cases. All simulations of the two industrial rotors are time–dependent, to capture the unsteadiness associated with stall which occurs at most wind speeds. The two designs are cross-compared, with emphasis on the different stall patterns resulting from particular design choices. The key novelty of this work is the CFD–based assessment of the correlation among turbine power, blade aerodynamics, and blade design variables (airfoil geometry, blade planform and twist) over most operational wind speeds.

ACS Style

A. G. Sanvito; G. Persico; M. S. Campobasso. Assessing the Sensitivity of Stall-Regulated Wind Turbine Power to Blade Design Using High-Fidelity CFD. Volume 9: Oil and Gas Applications; Supercritical CO2 Power Cycles; Wind Energy 2019, 1 .

AMA Style

A. G. Sanvito, G. Persico, M. S. Campobasso. Assessing the Sensitivity of Stall-Regulated Wind Turbine Power to Blade Design Using High-Fidelity CFD. Volume 9: Oil and Gas Applications; Supercritical CO2 Power Cycles; Wind Energy. 2019; ():1.

Chicago/Turabian Style

A. G. Sanvito; G. Persico; M. S. Campobasso. 2019. "Assessing the Sensitivity of Stall-Regulated Wind Turbine Power to Blade Design Using High-Fidelity CFD." Volume 9: Oil and Gas Applications; Supercritical CO2 Power Cycles; Wind Energy , no. : 1.

Chapter
Published: 07 February 2019 in Materials with Internal Structure
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ARCTIC, a novel incompressible Reynolds–averaged Navier–Stokes finite volume code for the hydrodynamic analysis of open rotor unsteady loads is presented. One of its unique features is a harmonic balance solver enabling high–fidelity analyses of turbine periodic hydrodynamic loads with runtimes reduced by more than one order of magnitude over conventional time–domain CFD, and with negligible accuracy penalty. The strength of the new technology is demonstrated by analyzing with both harmonic balance and time–domain solvers the load fluctuations of a realistic tidal stream turbine. Such fluctuations are caused by a harmonic perturbation of the freestream velocity similar to that due to surface gravity waves.

ACS Style

A. Cavazzini; M. S. Campobasso; M. Marconcini; R. Pacciani; A. Arnone. Harmonic Balance Navier–Stokes Analysis of Tidal Stream Turbine Wave Loads. Materials with Internal Structure 2019, 37 -49.

AMA Style

A. Cavazzini, M. S. Campobasso, M. Marconcini, R. Pacciani, A. Arnone. Harmonic Balance Navier–Stokes Analysis of Tidal Stream Turbine Wave Loads. Materials with Internal Structure. 2019; ():37-49.

Chicago/Turabian Style

A. Cavazzini; M. S. Campobasso; M. Marconcini; R. Pacciani; A. Arnone. 2019. "Harmonic Balance Navier–Stokes Analysis of Tidal Stream Turbine Wave Loads." Materials with Internal Structure , no. : 37-49.

Conference paper
Published: 04 November 2018 in ASME 2018 1st International Offshore Wind Technical Conference
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The unsteady aerodynamics of floating offshore wind turbine rotors is more complex than that of fixed-bottom turbine rotors, due to additional rigid-body motion components enabled by the lack of rigid foundations; it is still unclear if low-fidelity aerodynamic models, such as the blade element momentum theory, provide sufficiently reliable input for floating turbine design requiring load data for a wide range of operating conditions. High-fidelity Navies-Stokes CFD has the potential to improve the understanding of FOWT rotor aerodynamics, and support the improvement of lower-fidelity aerodynamic analysis models. To accomplish these aims, this study uses an in-house compressible Navier-Stokes code and the NREL FAST engineering code to analyze the unsteady flow regime of the NREL 5 MW rotor pitching with amplitude of 4° and frequency of 0.2 Hz, and compares all results to those obtained with a commercial incompressible code and FAST in a previous independent study. The level of agreement of CFD and engineering analyses in each of these two studies is found to be quantitatively similar, but the peak rotor power of the compressible flow analysis is about 20 % higher than that of the incompressible analysis. This is possibly due to compressibility effects, as the instantaneous local Mach number is found to be higher than 0.4. Validation of the compressible flow analysis set-up, using an absolute frame formulation and low-speed preconditioning, is based on the analysis of the steady and yawed flow past the NREL Phase VI rotor.

ACS Style

M. Sergio Campobasso; Andrea G. Sanvito; Jernej Drofelnik; Adrian Jackson; Yang Zhou; Qing Xiao; Alessandro Croce. Compressible Navier-Stokes Analysis of Floating Wind Turbine Rotor Aerodynamics. ASME 2018 1st International Offshore Wind Technical Conference 2018, 1 .

AMA Style

M. Sergio Campobasso, Andrea G. Sanvito, Jernej Drofelnik, Adrian Jackson, Yang Zhou, Qing Xiao, Alessandro Croce. Compressible Navier-Stokes Analysis of Floating Wind Turbine Rotor Aerodynamics. ASME 2018 1st International Offshore Wind Technical Conference. 2018; ():1.

Chicago/Turabian Style

M. Sergio Campobasso; Andrea G. Sanvito; Jernej Drofelnik; Adrian Jackson; Yang Zhou; Qing Xiao; Alessandro Croce. 2018. "Compressible Navier-Stokes Analysis of Floating Wind Turbine Rotor Aerodynamics." ASME 2018 1st International Offshore Wind Technical Conference , no. : 1.

Journal article
Published: 01 September 2018 in Computers & Fluids
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ACS Style

Adrian Jackson; M. Sergio Campobasso; Jernej Drofelnik. Load balance and parallel I/O: Optimising COSA for large simulations. Computers & Fluids 2018, 173, 206 -215.

AMA Style

Adrian Jackson, M. Sergio Campobasso, Jernej Drofelnik. Load balance and parallel I/O: Optimising COSA for large simulations. Computers & Fluids. 2018; 173 ():206-215.

Chicago/Turabian Style

Adrian Jackson; M. Sergio Campobasso; Jernej Drofelnik. 2018. "Load balance and parallel I/O: Optimising COSA for large simulations." Computers & Fluids 173, no. : 206-215.

Journal article
Published: 01 June 2018 in Aerospace Science and Technology
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Computational fluid dynamics codes using the density-based compressible flow formulation of the Navier-Stokes equations have proven to be very successful for the analysis of high-speed flows. However, solution accuracy degradation and, for explicit solvers, reduction of the residual convergence rates occur as the local Mach number decreases below the threshold of 0.1. This performance impairment worsens remarkably in the presence of flow reversals at wall boundaries and unbounded high-vorticity flow regions. These issues can be resolved using low-speed preconditioning, but there exists an outstanding problem regarding the use of this technology in the strongly coupled integration of the Reynolds-averaged Navier-Stokes equations and two-equation turbulence models, such as the k−ωk−ω shear stress transport model. It is not possible to precondition only the RANS equations without altering parts of the governing equations, and there did not exist an approach for preconditioning both the RANS and the SST equations. This study solves this problem by introducing a turbulent low-speed preconditioner of the RANS and SST equations that does not require any alteration of the governing equations. The approach has recently been shown to significantly improve convergence rates in the case of a one-equation turbulence model. The study focuses on the explicit multigrid integration of the governing equations, but most algorithms are applicable also to implicit integration methods. The paper provides all algorithms required for implementing the presented turbulent preconditioner in other computational fluid dynamics codes. The new method is applicable to all low- and mixed-speed aeronautical and propulsion flow problems, and is demonstrated by analyzing the flow field of a Darrieus wind turbine rotor section at two operating conditions, one of which is characterized by significant blade/vortex interaction. Verification and further validation of the new method is also based on the comparison of the results obtained with the developed density-based code and those obtained with a commercial pressure-based code.

ACS Style

M.S. Campobasso; M. Yan; A. Bonfiglioli; F.A. Gigante; L. Ferrari; F. Balduzzi; A. Bianchini. Low-speed preconditioning for strongly coupled integration of Reynolds-averaged Navier–Stokes equations and two-equation turbulence models. Aerospace Science and Technology 2018, 77, 286 -298.

AMA Style

M.S. Campobasso, M. Yan, A. Bonfiglioli, F.A. Gigante, L. Ferrari, F. Balduzzi, A. Bianchini. Low-speed preconditioning for strongly coupled integration of Reynolds-averaged Navier–Stokes equations and two-equation turbulence models. Aerospace Science and Technology. 2018; 77 ():286-298.

Chicago/Turabian Style

M.S. Campobasso; M. Yan; A. Bonfiglioli; F.A. Gigante; L. Ferrari; F. Balduzzi; A. Bianchini. 2018. "Low-speed preconditioning for strongly coupled integration of Reynolds-averaged Navier–Stokes equations and two-equation turbulence models." Aerospace Science and Technology 77, no. : 286-298.

Research article
Published: 30 March 2018 in Wind Energy
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Multimegawatt horizontal axis wind turbines often operate in yawed wind transients, in which the resulting periodic loads acting on blades, drive‐train, tower, and foundation adversely impact on fatigue life. Accurately predicting yawed wind turbine aerodynamics and resulting structural loads can be challenging and would require the use of computationally expensive high‐fidelity unsteady Navier‐Stokes computational fluid dynamics. The high computational cost of this approach can be significantly reduced by using a frequency‐domain framework. The paper summarizes the main features of the COSA harmonic balance Navier‐Stokes solver for the analysis of open rotor periodic flows, presents initial validation results on the basis of the analysis of the NREL Phase VI experiment, and it also provides a sample application to the analysis of a multimegawatt turbine in yawed wind. The reported analyses indicate that the harmonic balance solver determines the considered periodic flows from 30 to 50 times faster than the conventional time‐domain approach with negligible accuracy penalty to the latter.

ACS Style

Jernej Drofelnik; Andrea Da Ronch; Michele Sergio Campobasso. Harmonic balance Navier-Stokes aerodynamic analysis of horizontal axis wind turbines in yawed wind. Wind Energy 2018, 21, 515 -530.

AMA Style

Jernej Drofelnik, Andrea Da Ronch, Michele Sergio Campobasso. Harmonic balance Navier-Stokes aerodynamic analysis of horizontal axis wind turbines in yawed wind. Wind Energy. 2018; 21 (7):515-530.

Chicago/Turabian Style

Jernej Drofelnik; Andrea Da Ronch; Michele Sergio Campobasso. 2018. "Harmonic balance Navier-Stokes aerodynamic analysis of horizontal axis wind turbines in yawed wind." Wind Energy 21, no. 7: 515-530.

Journal article
Published: 03 October 2017 in Journal of Engineering for Gas Turbines and Power
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Due to the rapid progress in high-performance computing and the availability of increasingly large computational resources, Navier–Stokes (NS) computational fluid dynamics (CFD) now offers a cost-effective, versatile, and accurate means to improve the understanding of the unsteady aerodynamics of Darrieus wind turbines and deliver more efficient designs. In particular, the possibility of determining a fully resolved flow field past the blades by means of CFD offers the opportunity to both further understand the physics underlying the turbine fluid dynamics and to use this knowledge to validate lower-order models, which can have a wider diffusion in the wind energy sector, particularly for industrial use, in the light of their lower computational burden. In this context, highly spatially and temporally refined time-dependent three-dimensional (3D) NS simulations were carried out using more than 16,000 processor cores per simulation on an IBM BG/Q cluster in order to investigate thoroughly the 3D unsteady aerodynamics of a single blade in Darrieus-like motion. Particular attention was paid to tip losses, dynamic stall, and blade/wake interaction. CFD results are compared with those obtained with an open-source code based on the lifting line free vortex wake model (LLFVW). At present, this approach is the most refined method among the “lower-fidelity” models, and as the wake is explicitly resolved in contrast to blade element momentum (BEM)-based methods, LLFVW analyses provide 3D flow solutions. Extended comparisons between the two approaches are presented and a critical analysis is carried out to identify the benefits and drawbacks of the two approaches.

ACS Style

Francesco Balduzzi; David Marten; Alessandro Bianchini; Jernej Drofelnik; Lorenzo Ferrari; Michele Sergio Campobasso; Georgios Pechlivanoglou; Christian Navid Nayeri; Giovanni Ferrara; Christian Oliver Paschereit. Three-Dimensional Aerodynamic Analysis of a Darrieus Wind Turbine Blade Using Computational Fluid Dynamics and Lifting Line Theory. Journal of Engineering for Gas Turbines and Power 2017, 140, 022602 .

AMA Style

Francesco Balduzzi, David Marten, Alessandro Bianchini, Jernej Drofelnik, Lorenzo Ferrari, Michele Sergio Campobasso, Georgios Pechlivanoglou, Christian Navid Nayeri, Giovanni Ferrara, Christian Oliver Paschereit. Three-Dimensional Aerodynamic Analysis of a Darrieus Wind Turbine Blade Using Computational Fluid Dynamics and Lifting Line Theory. Journal of Engineering for Gas Turbines and Power. 2017; 140 (2):022602.

Chicago/Turabian Style

Francesco Balduzzi; David Marten; Alessandro Bianchini; Jernej Drofelnik; Lorenzo Ferrari; Michele Sergio Campobasso; Georgios Pechlivanoglou; Christian Navid Nayeri; Giovanni Ferrara; Christian Oliver Paschereit. 2017. "Three-Dimensional Aerodynamic Analysis of a Darrieus Wind Turbine Blade Using Computational Fluid Dynamics and Lifting Line Theory." Journal of Engineering for Gas Turbines and Power 140, no. 2: 022602.

Conference paper
Published: 26 June 2017 in Volume 2A: Turbomachinery
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Due to the rapid progress in high-performance computing and the availability of increasingly large computational resources, Navier-Stokes computational fluid dynamics (CFD) now offers a cost-effective, versatile and accurate means to improve the understanding of the unsteady aerodynamics of Darrieus wind turbines and deliver more efficient designs. In particular, the possibility of determining a fully resolved flow field past the blades by means of CFD offers the opportunity to both further understand the physics underlying the turbine fluid dynamics and to use this knowledge to validate lower-order models, which can have a wider diffusion in the wind energy sector, particularly for industrial use, in the light of their lower computational burden. In this context, highly spatially and temporally refined time-dependent three-dimensional Navier-Stokes simulations were carried out using more than 16,000 processor cores per simulation on an IBM BG/Q cluster in order to investigate thoroughly the three-dimensional unsteady aerodynamics of a single blade in Darrieus-like motion. Particular attention was payed to tip losses, dynamic stall, and blade/wake interaction. CFD results are compared with those obtained with an open-source code based on the Lifting Line Free Vortex Wake Model (LLFVW). At present, this approach is the most refined method among the “lower-fidelity” models and, as the wake is explicitly resolved in contrast to BEM-based methods, LLFVW analyses provide three-dimensional flow solutions. Extended comparisons between the two approaches are presented and a critical analysis is carried out to identify the benefits and drawbacks of the two approaches.

ACS Style

Francesco Balduzzi; Alessandro Bianchini; Giovanni Ferrara; David Marten; George Pechlivanoglou; Christian Navid Nayeri; Christian Oliver Paschereit; Jernej Drofelnik; Michele Sergio Campobasso; Lorenzo Ferrari. Three-Dimensional Aerodynamic Analysis of a Darrieus Wind Turbine Blade Using Computational Fluid Dynamics and Lifting Line Theory. Volume 2A: Turbomachinery 2017, 1 .

AMA Style

Francesco Balduzzi, Alessandro Bianchini, Giovanni Ferrara, David Marten, George Pechlivanoglou, Christian Navid Nayeri, Christian Oliver Paschereit, Jernej Drofelnik, Michele Sergio Campobasso, Lorenzo Ferrari. Three-Dimensional Aerodynamic Analysis of a Darrieus Wind Turbine Blade Using Computational Fluid Dynamics and Lifting Line Theory. Volume 2A: Turbomachinery. 2017; ():1.

Chicago/Turabian Style

Francesco Balduzzi; Alessandro Bianchini; Giovanni Ferrara; David Marten; George Pechlivanoglou; Christian Navid Nayeri; Christian Oliver Paschereit; Jernej Drofelnik; Michele Sergio Campobasso; Lorenzo Ferrari. 2017. "Three-Dimensional Aerodynamic Analysis of a Darrieus Wind Turbine Blade Using Computational Fluid Dynamics and Lifting Line Theory." Volume 2A: Turbomachinery , no. : 1.

Journal article
Published: 01 June 2017 in Energy
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Energized by the recent rapid progress in high-performance computing and the growing availability of large computational resources, computational fluid dynamics (CFD) is offering a cost-effective, versatile and accurate means to improve the understanding of the unsteady aerodynamics of Darrieus wind turbines, increase their efficiency and delivering more cost-effective and structurally sound designs. In this study, a Navier-Stokes CFD research code featuring a very high parallel efficiency was used to thoroughly investigate the three-dimensional unsteady aerodynamics of a Darrieus rotor blade. Highly spatially and temporally resolved unsteady simulations were carried out using more than 16,000 processor cores on an IBM BG/Q cluster. The study aims at providing a detailed description and quantification of the main three-dimensional effects associated with the periodic motion of this turbine type, including tip losses, dynamic stall, vortex propagation and blade/wake interaction. Presented results reveal that the three-dimensional flow effects affecting Darrieus rotor blades are significantly more complex than assumed by the lower-fidelity models often used for design applications, and strongly vary during the rotor revolution. A comparison of the CFD integral estimates and the results of a blade-element momentum code is also presented to highlight strengths and weaknesses of low-fidelity codes for Darrieus turbine design. The reported CFD results may provide a valuable and reliable benchmark for the calibration of lower-fidelity models, which are still key to industrial design due to their very high execution speed

ACS Style

Francesco Balduzzi; Jernej Drofelnik; Alessandro Bianchini; Giovanni Ferrara; Lorenzo Ferrari; Michele Sergio Campobasso. Darrieus wind turbine blade unsteady aerodynamics: a three-dimensional Navier-Stokes CFD assessment. Energy 2017, 128, 550 -563.

AMA Style

Francesco Balduzzi, Jernej Drofelnik, Alessandro Bianchini, Giovanni Ferrara, Lorenzo Ferrari, Michele Sergio Campobasso. Darrieus wind turbine blade unsteady aerodynamics: a three-dimensional Navier-Stokes CFD assessment. Energy. 2017; 128 ():550-563.

Chicago/Turabian Style

Francesco Balduzzi; Jernej Drofelnik; Alessandro Bianchini; Giovanni Ferrara; Lorenzo Ferrari; Michele Sergio Campobasso. 2017. "Darrieus wind turbine blade unsteady aerodynamics: a three-dimensional Navier-Stokes CFD assessment." Energy 128, no. : 550-563.

Journal article
Published: 01 December 2016 in International Journal of Marine Energy
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Oscillating wings can extract energy from an oncoming water or air stream, and first large-scale marine demonstrators are being tested. Oscillating wing hydrodynamics is highly unsteady, may feature dynamic stall and leading edge vortex shedding, and is significantly three-dimensional due to finite-wing effects. Understanding the interaction of these phenomena is essential for maximizing power generation efficiency. Much of the knowledge on oscillating wing hydrodynamics stemmed from two-dimensional low-Reynolds number computational fluid dynamics studies and laboratory testing; real installations, however, will feature Reynolds numbers higher than 1 million and unavoidable finite-wing-induced losses. This study investigates the impact of flow three-dimensionality on the hydrodynamics and the efficiency of a realistic aspect ratio 10 device in a stream with Reynolds number of 1.5 million. The improvements achievable by using endplates to reduce finite-wing-induced losses are also analyzed. Three-dimensional time-dependent Navier-Stokes simulations using the shear stress transport turbulence model and a 30 million-cell grid are performed. Detailed comparative hydrodynamic analyses of the finite and the infinite wings reveal that flow three-dimensionality reduces the power generation efficiency of the finite wing with sharp tips and that with endplates by about 17% and 12% respectively. Presented analyses suggest approaches to further reducing these power losses

ACS Style

Jernej Drofelnik; Michele Sergio Campobasso. Comparative turbulent three-dimensional Navier–Stokes hydrodynamic analysis and performance assessment of oscillating wings for renewable energy applications. International Journal of Marine Energy 2016, 16, 100 -115.

AMA Style

Jernej Drofelnik, Michele Sergio Campobasso. Comparative turbulent three-dimensional Navier–Stokes hydrodynamic analysis and performance assessment of oscillating wings for renewable energy applications. International Journal of Marine Energy. 2016; 16 ():100-115.

Chicago/Turabian Style

Jernej Drofelnik; Michele Sergio Campobasso. 2016. "Comparative turbulent three-dimensional Navier–Stokes hydrodynamic analysis and performance assessment of oscillating wings for renewable energy applications." International Journal of Marine Energy 16, no. : 100-115.

Journal article
Published: 01 September 2016 in Computers & Fluids
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Several important wind turbine unsteady flow regimes, such as those associated with the yawed wind condition of horizontal axis machines, and most operating conditions of all vertical axis machines, are predominantly periodic. The harmonic balance Reynolds-averaged Navier-Stokes technology for the rapid calculation of nonlinear periodic flow fields has been successfully used to greatly reduce runtimes of turbomachinery periodic flow analyses in the past fifteen years. This paper presents an objective comparative study of the performance and solution accuracy of this technology for aerodynamic analysis and design applications of horizontal and vertical axis wind turbines. The considered use cases are the periodic flow past the blade section of a utility-scale horizontal axis wind turbine rotor in yawed wind, and the periodic flow of a H-Darrieus rotor section working at a tip-speed ratio close to that of maximum power. The aforementioned comparative assessment is based on thorough parametric time-domain and harmonic balance analyses of both use cases. The paper also reports the main mathematical and numerical features of a new turbulent harmonic balance Navier-Stokes solver using Menter’s shear stress transport model for the turbulence closure. Presented results indicate that a) typical multimegawatt horizontal axis wind turbine periodic flows can be computed by the harmonic balance solver about ten times more rapidly than by the conventional time-domain analysis, achieving the same temporal accuracy of the latter method, and b) the harmonic balance acceleration for Darrieus rotor unsteady flow analysis is lower than for horizontal axis machines, and the harmonic balance solutions feature undesired oscillations caused by the wide harmonic content and the high-level of stall predisposition of this flow field type.

ACS Style

M. Sergio Campobasso; Jernej Drofelnik; Fabio Gigante. Comparative assessment of the harmonic balance Navier–Stokes technology for horizontal and vertical axis wind turbine aerodynamics. Computers & Fluids 2016, 136, 354 -370.

AMA Style

M. Sergio Campobasso, Jernej Drofelnik, Fabio Gigante. Comparative assessment of the harmonic balance Navier–Stokes technology for horizontal and vertical axis wind turbine aerodynamics. Computers & Fluids. 2016; 136 ():354-370.

Chicago/Turabian Style

M. Sergio Campobasso; Jernej Drofelnik; Fabio Gigante. 2016. "Comparative assessment of the harmonic balance Navier–Stokes technology for horizontal and vertical axis wind turbine aerodynamics." Computers & Fluids 136, no. : 354-370.