The Experts below are selected from a list of 9 Experts worldwide ranked by ideXlab platform

Vinhtan Nguyen - One of the best experts on this subject based on the ideXlab platform.

  • aerodynamic simulations of offshore floating wind turbine in platform induced pitching motion
    Wind Energy, 2017
    Co-Authors: Vinhtan Nguyen
    Abstract:

    Forfloating offshore wind turbines, rotors are under coupled motions of rotating and platform-induced motions because of hydrodynamics impacts. Notably, the coupled motion of platform pitching and rotor rotating induces unsteadiness and nonlinear aerodynamics in turbine operations; thus having a strong effect on the rotor performances including Thrust and power generation. The present work aims at developing a computational fluid dynamics model for simulations of rotor under floating platform induced motions. The rotor motion is realized using arbitrary mesh interface, and wind flows are modelled by incompressible Navier-Stokes flow solver appended by the k − ω shear stress transport turbulence model to resolve turbulence quantities. In order to investigate the fully coupled motion of floating wind turbine, the six degree of freedom solid body motion solver is extended to couple with multiple motions, especially for the motion of rotor coupled with the prescribed surge-heave-pitch motion of floating platform. The detailed methodology of multiple motion coupling is also described and discussed in this work. Both steady and unsteady simulations of offshore floating wind turbine are considered in the present work. The steady aerodynamic simulation of offshore floating wind turbine is implemented by the multiple reference frames approach and for the transient simulation, the rotor motion is realized using arbitrary mesh interface. A rigorous benchmark of the present numerical model is performed by comparing to the reported literatures. The detailed Elemental Thrust and power comparisons of wind turbine are carried out by comparing with the results from FAST developed by National Renewable Energy Laboratory and various existing numerical data with good agreement. The proposed approach is then applied for simulations of National Renewable Energy Laboratory 5MW turbine in coupled platform motion at various wind speeds under a typical load case scenario. Transient effect of flows over turbines rotor is captured with good prediction of turbine performance as compared with existing data from FAST. Copyright © 2016 John Wiley & Sons, Ltd.

  • Lloyd's Register Global
    2015
    Co-Authors: Anand Bahuguni, Krishnamoorthi Sivalingam, Peter Davies, Johan Gullman-strand, Technology Centre, Vinhtan Nguyen
    Abstract:

    Most of the wind turbine analysis softwares widely being used in the market are based on the Blade Element Momentum method (BEM). The two important parameters that the BEM codes calculate are the axial and the tangential induction factors. These factors are calculated based on the empirical blade lift coefficient Cl and drag coefficient Cd along with some loss/correction functions to account for the losses near the blade tip and the hub. The current study focusses on verifying the values of induction factors using Computational Fluid Dynamics (CFD) simulations for floating offshore wind turbines at a selected sea state. The study includes steady state calculations as well as transient calculations for pitching motions of the turbine due to waves. The NREL FAST software is used to set the simulation scenarios according to OC3 Phase IV cases. The blades are divided a number of elements in CFD calculations and the data are extracted at individual elements to have an exact comparison with the BEM based calculations. NOMENCLATURE B- number of blades dr- blade element length in radial direction dT- Elemental torque (BEM based) dF- Elemental Thrust (BEM based) dTCFD- CFD based Elemental torque dFCFD- CFD based Elemental Thrust F- overall loss factor Ft- prandtl tip loss factor Fh- hub loss facto

Anand Bahuguni - One of the best experts on this subject based on the ideXlab platform.

  • Lloyd's Register Global
    2015
    Co-Authors: Anand Bahuguni, Krishnamoorthi Sivalingam, Peter Davies, Johan Gullman-strand, Technology Centre, Vinhtan Nguyen
    Abstract:

    Most of the wind turbine analysis softwares widely being used in the market are based on the Blade Element Momentum method (BEM). The two important parameters that the BEM codes calculate are the axial and the tangential induction factors. These factors are calculated based on the empirical blade lift coefficient Cl and drag coefficient Cd along with some loss/correction functions to account for the losses near the blade tip and the hub. The current study focusses on verifying the values of induction factors using Computational Fluid Dynamics (CFD) simulations for floating offshore wind turbines at a selected sea state. The study includes steady state calculations as well as transient calculations for pitching motions of the turbine due to waves. The NREL FAST software is used to set the simulation scenarios according to OC3 Phase IV cases. The blades are divided a number of elements in CFD calculations and the data are extracted at individual elements to have an exact comparison with the BEM based calculations. NOMENCLATURE B- number of blades dr- blade element length in radial direction dT- Elemental torque (BEM based) dF- Elemental Thrust (BEM based) dTCFD- CFD based Elemental torque dFCFD- CFD based Elemental Thrust F- overall loss factor Ft- prandtl tip loss factor Fh- hub loss facto

Krishnamoorthi Sivalingam - One of the best experts on this subject based on the ideXlab platform.

  • Lloyd's Register Global
    2015
    Co-Authors: Anand Bahuguni, Krishnamoorthi Sivalingam, Peter Davies, Johan Gullman-strand, Technology Centre, Vinhtan Nguyen
    Abstract:

    Most of the wind turbine analysis softwares widely being used in the market are based on the Blade Element Momentum method (BEM). The two important parameters that the BEM codes calculate are the axial and the tangential induction factors. These factors are calculated based on the empirical blade lift coefficient Cl and drag coefficient Cd along with some loss/correction functions to account for the losses near the blade tip and the hub. The current study focusses on verifying the values of induction factors using Computational Fluid Dynamics (CFD) simulations for floating offshore wind turbines at a selected sea state. The study includes steady state calculations as well as transient calculations for pitching motions of the turbine due to waves. The NREL FAST software is used to set the simulation scenarios according to OC3 Phase IV cases. The blades are divided a number of elements in CFD calculations and the data are extracted at individual elements to have an exact comparison with the BEM based calculations. NOMENCLATURE B- number of blades dr- blade element length in radial direction dT- Elemental torque (BEM based) dF- Elemental Thrust (BEM based) dTCFD- CFD based Elemental torque dFCFD- CFD based Elemental Thrust F- overall loss factor Ft- prandtl tip loss factor Fh- hub loss facto

Peter Davies - One of the best experts on this subject based on the ideXlab platform.

  • Lloyd's Register Global
    2015
    Co-Authors: Anand Bahuguni, Krishnamoorthi Sivalingam, Peter Davies, Johan Gullman-strand, Technology Centre, Vinhtan Nguyen
    Abstract:

    Most of the wind turbine analysis softwares widely being used in the market are based on the Blade Element Momentum method (BEM). The two important parameters that the BEM codes calculate are the axial and the tangential induction factors. These factors are calculated based on the empirical blade lift coefficient Cl and drag coefficient Cd along with some loss/correction functions to account for the losses near the blade tip and the hub. The current study focusses on verifying the values of induction factors using Computational Fluid Dynamics (CFD) simulations for floating offshore wind turbines at a selected sea state. The study includes steady state calculations as well as transient calculations for pitching motions of the turbine due to waves. The NREL FAST software is used to set the simulation scenarios according to OC3 Phase IV cases. The blades are divided a number of elements in CFD calculations and the data are extracted at individual elements to have an exact comparison with the BEM based calculations. NOMENCLATURE B- number of blades dr- blade element length in radial direction dT- Elemental torque (BEM based) dF- Elemental Thrust (BEM based) dTCFD- CFD based Elemental torque dFCFD- CFD based Elemental Thrust F- overall loss factor Ft- prandtl tip loss factor Fh- hub loss facto

Johan Gullman-strand - One of the best experts on this subject based on the ideXlab platform.

  • Lloyd's Register Global
    2015
    Co-Authors: Anand Bahuguni, Krishnamoorthi Sivalingam, Peter Davies, Johan Gullman-strand, Technology Centre, Vinhtan Nguyen
    Abstract:

    Most of the wind turbine analysis softwares widely being used in the market are based on the Blade Element Momentum method (BEM). The two important parameters that the BEM codes calculate are the axial and the tangential induction factors. These factors are calculated based on the empirical blade lift coefficient Cl and drag coefficient Cd along with some loss/correction functions to account for the losses near the blade tip and the hub. The current study focusses on verifying the values of induction factors using Computational Fluid Dynamics (CFD) simulations for floating offshore wind turbines at a selected sea state. The study includes steady state calculations as well as transient calculations for pitching motions of the turbine due to waves. The NREL FAST software is used to set the simulation scenarios according to OC3 Phase IV cases. The blades are divided a number of elements in CFD calculations and the data are extracted at individual elements to have an exact comparison with the BEM based calculations. NOMENCLATURE B- number of blades dr- blade element length in radial direction dT- Elemental torque (BEM based) dF- Elemental Thrust (BEM based) dTCFD- CFD based Elemental torque dFCFD- CFD based Elemental Thrust F- overall loss factor Ft- prandtl tip loss factor Fh- hub loss facto