The Experts below are selected from a list of 7554 Experts worldwide ranked by ideXlab platform

Haisheng Chen - One of the best experts on this subject based on the ideXlab platform.

  • coupling optimization of casing groove and Blade Profile for a radial turbine
    Proceedings of the Institution of Mechanical Engineers Part A: Journal of Power and Energy, 2021
    Co-Authors: Xing Wang, Xuehui Zhang, Haisheng Chen
    Abstract:

    In order to suppress the tip leakage loss and increase the isentropic efficiency in a radial turbine with low aspect ratio Blade, a new coupling flow control technology including casing groove and ...

  • Efficiency improvement of a CAES low aspect ratio radial inflow turbine by NACA Blade Profile
    Renewable Energy, 2019
    Co-Authors: Wang Xing, Zhang Xuehui, Zhu Yangli, Zhitao Zuo, Haisheng Chen
    Abstract:

    Compressed Air Energy Storage (CAES) System is a significant technology for renewable energy utilization. As a power generation device in the system, the Blade of radial inflow turbine has a lower aspect ratio and tip leakage loss is larger. A novel Blade Profile based on NACA standard airfoil is proposed and optimized by orthogonal design coupling Computational Fluid Dynamic (CFD) model. The effect of NACA-based Profile parameters on isentropic efficiency is obtained and the tip leakage flow loss mechanism is revealed. The applicability of Blade with optimal NACA-based Profile is investigated under off-design operation and non-uniformity inlet conditions. Results indicate that the optimal NACA-based Profile has larger leading edge inscribed circle radius and smaller thickness at trail part of Blade which reduces the tip leakage flow velocity near trailing edge and weakens the mixing of the leakage flow and mainstream. As a result, the efficiency of the radial inflow turbine can be increased by 1.26%, 1.20% and 1.99% when the tip clearance are 2%, 4%, and 8%, respectively. The Blade with optimal NACA-based Profile also increases the efficiency of the radial inflow turbine at different pressure ratios and inlet attack angles and satisfies the deformation and structure strength requirement.

Per Horlyck Nielsen - One of the best experts on this subject based on the ideXlab platform.

  • design optimization of a 5 mw floating offshore vertical axis wind turbine
    Energy Procedia, 2013
    Co-Authors: Uwe Schmidt Paulsen, Ismet Baran, Jesper Henri Hattel, H Madsen, Per Horlyck Nielsen
    Abstract:

    This paper outlines results of a proposed layout of a light 2-Bladed rotor, with a driving torque constraint matching the generator design, and shows details of the pultruded Blade – and rotor geometry. In comparison with the 1st baseline design of a 5 MW VAWT concept this present development provides during standstill and operation significant less mass with a comparable level of loading strain in the Blades and in the junctions between Blade and tower. Optimized Blade Profile having a low weight and high stiffness is obtained according to the design evaluations based on the standstill calculations in ANSYS software. The selected Profiles are used in the aero dynamic simulation. Furthermore the simulation code will be demonstrated to show the fully development model, integrating the simulation of turbulent wind inflow, actuator cylinder flow model, power controls, hydraulic floater - and mooring line systems implementation.

R. Abdulhadi - One of the best experts on this subject based on the ideXlab platform.

  • The performance of Wells turbine under bi-directional airflow
    Renewable Energy, 2008
    Co-Authors: A. Thakker, R. Abdulhadi
    Abstract:

    This paper presents the performance of a Wells turbine operating under unsteady bi-directional airflow conditions. In this study, four kinds of Blade Profile were selected, NACA0020, NACA0015, CA9 and HSIM 15-262123-1576. The experiments have been carried out for two solidities under sinusoidal and irregular unsteady flow conditions based on Irish waves (Site2). It was found that for a Wells turbine operating under bi-directional air flow, the rotor geometry preferred is the Blade Profile of CA9 with rotor solidity σ=0.64. In addition, the efficiency curve of the Wells turbine under unidirectional flow conditions fails to present the rapid rise in the instantaneous efficiency which occurs at low flow coefficient of bi-directional flow condition. A comparative analysis between the numerical simulation results and experimental results was carried out. As a result, an excellent agreement was found between the numerical and experimental results. In addition, the effect of Blade Profile and rotor solidity on hysteretic characteristics of the turbine has been clarified experimentally under bi-directional airflow.

  • effect of Blade Profile on the performance of wells turbine under unidirectional sinusoidal and real sea flow conditions
    International Journal of Rotating Machinery, 2007
    Co-Authors: A. Thakker, R. Abdulhadi
    Abstract:

    This paper presents the effect of Blade Profile and rotor solidity on the performance of Wells turbine operating under unidirectional unsteady flow conditions. In the study, four kinds of Blade Profile were selected, that is, NACA0020, NACA0015, CA9, and HSIM 15-262123-1576. The experiments have been carried out for two solidities, σ = 0.48 and σ = 0.64, under sinusoidal and irregular unsteady flow conditions based on Irish waves (site2). As a result, it was found that the preferable rotor geometry is the one with Blade Profile of CA9 with solidity σ = 0.64. In addition, the effect of Blade Profile and rotor solidity on hysteretic characteristics of the turbine has been clarified experimentally and it was found to be in good agreement qualitatively when compared to numerical results (Setoguchi et al. (2003)).

  • Effect of Blade Profile on the performance of a large-scale Wells turbine for wave-energy conversion
    International Journal of Sustainable Energy, 2006
    Co-Authors: A. Thakker, R. Abdulhadi
    Abstract:

    The aim of this study is to clarify the effect of rotor Blade Profile on the performance of the Wells turbine operated at high Reynolds number. In the study, four kinds of Blade Profile were selected with regard to the Blade Profile of the Wells turbine. The types of Blade Profile are as follows: NACA0020, NACA0015, CA9, and HSIM 15-262123-1576. In order to determine the optimum rotor Blade Profile of the turbine, experimental investigations have been performed for two solidities by model testing and numerical simulation. As a result, it has been concluded that a suitable choice, namely the preferable rotor geometry, is the Blade Profile of NACA0015. Furthermore, it has been found that the critical Reynolds number of the turbine is around 4×105.

  • Effect of Blade Profile on the Performance of Large-Scale Wells Turbine
    2004
    Co-Authors: A. Thakker, R. Abdulhadi
    Abstract:

    The aim of this study is to clarify the effect of rotor Blade Profile on the performance of the Wells turbine operated at high Reynolds number. In the study, four kinds of Blade Profile were selected with regard to the Blade Profile of the Wells turbine. The experimental investigations have been performed for two solidities by model testing and numerical simulation. As a result, it has been concluded that a suitable choice, namely the preferable rotor geometry, is the Blade Profile of NACA0015. Furthermore, it has been found that the critical Reynolds number of the turbine seems to be around 4×10 5 .

Muhammad S. Virk - One of the best experts on this subject based on the ideXlab platform.

  • study of ice accretion and icing effects on aerodynamic characteristics of du96 wind turbine Blade Profile
    Cold Regions Science and Technology, 2019
    Co-Authors: Jia Yi Jin, Muhammad S. Virk
    Abstract:

    Abstract In order to optimize the large wind turbines operation in ice prone cold regions, it is important to better understand the ice accretion physics and its effects on aerodynamic performance and power production losses. This paper describes a case study of ice accretion on DU96-W-180 airfoil, which has been used for large wind turbine Blades such as NREL 5 MW. Analysis has been carried out for glaze and rime ice conditions using icing tunnel experimental data and multiphase Computational Fluid Dynamics (CFD) based numerical approach. Results show a difference in Profile surface roughness and heat fluxes during rime and glaze ice accretion process, which leads to a significant change in rate and shape of ice accretion. More complex ice shapes are observed in case of glaze ice conditions that affects the aerodynamic performance differently from rime ice conditions. Numerical results are compared with the experimental data, where a good agreement is found. Results show higher aerodynamic performance degradation for glaze ice conditions particularly at higher angles of attack.

  • wind turbine Blade Profile thickness effects on atmospheric ice accretion
    IEEE International Conference on Power and Renewable Energy, 2016
    Co-Authors: Muhammad S. Virk
    Abstract:

    Choice of Blade Profile (airfoil) is a crucial step in wind turbine design for cold climate operations in order to obtain a competitive performance and to make a tradeoff between aerodynamic performance and structural requirements. A numerical study has been carried out to understand the effects of wind turbine Blade Profile geometric thickness on resultant ice accretion. Five different Blade Profiles (airfoils) were used for this study. Based upon the flow field calculations and the super cooled water droplet collision efficiency, rate and shape of accreted ice was simulated for dry ice conditions on each airfoil. Analysis showed a change in airflow and droplet behavior with the Blade Profile thickness. Results show a decrease in ice growth and thickness at leading edge of the Blade Profile with the increase of its thickness.

  • effect of atmospheric temperature and droplet size variation on ice accretion of wind turbine Blades
    Journal of Wind Engineering and Industrial Aerodynamics, 2010
    Co-Authors: Matthew C Homola, Tomas Wallenius, Per Johan Nicklasson, Muhammad S. Virk, Per A Sundsbo
    Abstract:

    Abstract A numerical study of ice accretion and the resultant flow field characteristics of a 5 MW pitch controlled wind turbine Blade Profile (NACA 64618) have been carried out to understand the effects that atmospheric temperature and droplet size variations have on the rate and shape of ice growth. Resultant aerodynamic characteristics of the Blade Profile were analysed at different angles of attack ranging from −10° to +20°. Results show an increase in the ice growth with the increase of droplet size; whereas change in atmospheric temperature significantly affects the shape of accreted ice. Streamlined ice shapes were observed for low temperatures, whereas horn shape ice accretion was found at higher temperatures. Results show that for the iced Blade Profiles, changes in the aerodynamic characteristics are least prominent for the case of rime ice as compared to glaze ice.

  • effect of rime ice accretion on aerodynamic characteristics of wind turbine Blade Profiles
    Wind Engineering, 2010
    Co-Authors: Muhammad S. Virk, Matthew C Homola, Per Johan Nicklasson
    Abstract:

    A numerical study of rime ice accretion and resultant flow field characteristics of Blade Profiles for four different fixed speed, stall controlled wind turbines was performed. Analyses were carried out at Reynolds numbers ranging from of 2.5 x 106 to 5.5 x 106, corresponding to the operational wind speeds and angles of attack ranging from -10 degree to + 20 degree. Numerical analyses showed that an increase in Blade Profile size reduces the dry rime ice accretion at leading edge, both in terms of local mass and ice thickness. A significant change in the flow behaviour and aerodynamic characteristics is observed, when a comparison is made between plain and iced Blade Profiles. Results showed an increase in both lift and drag coefficients of wind turbine Blade Profiles with the leading edge ice.

Wang Xing - One of the best experts on this subject based on the ideXlab platform.

  • Efficiency improvement of a CAES low aspect ratio radial inflow turbine by NACA Blade Profile
    Renewable Energy, 2019
    Co-Authors: Wang Xing, Zhang Xuehui, Zhu Yangli, Zhitao Zuo, Haisheng Chen
    Abstract:

    Compressed Air Energy Storage (CAES) System is a significant technology for renewable energy utilization. As a power generation device in the system, the Blade of radial inflow turbine has a lower aspect ratio and tip leakage loss is larger. A novel Blade Profile based on NACA standard airfoil is proposed and optimized by orthogonal design coupling Computational Fluid Dynamic (CFD) model. The effect of NACA-based Profile parameters on isentropic efficiency is obtained and the tip leakage flow loss mechanism is revealed. The applicability of Blade with optimal NACA-based Profile is investigated under off-design operation and non-uniformity inlet conditions. Results indicate that the optimal NACA-based Profile has larger leading edge inscribed circle radius and smaller thickness at trail part of Blade which reduces the tip leakage flow velocity near trailing edge and weakens the mixing of the leakage flow and mainstream. As a result, the efficiency of the radial inflow turbine can be increased by 1.26%, 1.20% and 1.99% when the tip clearance are 2%, 4%, and 8%, respectively. The Blade with optimal NACA-based Profile also increases the efficiency of the radial inflow turbine at different pressure ratios and inlet attack angles and satisfies the deformation and structure strength requirement.