The Experts below are selected from a list of 249 Experts worldwide ranked by ideXlab platform

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

  • Experimental Investigation of Transient Characteristics of a Double Suction Centrifugal Pump System during Starting Period
    Energies, 2019
    Co-Authors: Faye Jin, Zhifeng Yao, Ruofu Xiao, Fujun Wang
    Abstract:

    The starting phase for pumps in water transportation pipelines is crucial and has significant transient characteristics which merit further study in order to evaluate the operational stability of the pumping system. This paper presents the results of a study in which the relative steady operating conditions and starting period of a large double-suction centrifugal pump were monitored in real time, including pressure fluctuations, shaft run-out and vibration at the bearing. The transient characteristics of a double-suction centrifugal pump under different operating conditions have been analyzed using fast Fourier transform (FFT) and continuous wavelet transform (CWT). Results indicate broadband Frequency components within the spectrum of pressure fluctuations in the volute casing under all test conditions, and the central Frequency of the broadband Frequency gradually decreases as flow rate increases and approaches the Blade Frequency, which is the primary reason for an increase in Blade-Frequency amplitude. This may produce a vibration Frequency that is similar to the natural Frequency of a certain part of the double-suction centrifugal pump during the starting period, which causes the resonance phenomenon. The radial force is also large during the starting period, which causes eccentric wear of the seal ring at the impeller inlet.

Faye Jin - One of the best experts on this subject based on the ideXlab platform.

  • Experimental Investigation of Transient Characteristics of a Double Suction Centrifugal Pump System during Starting Period
    Energies, 2019
    Co-Authors: Faye Jin, Zhifeng Yao, Ruofu Xiao, Fujun Wang
    Abstract:

    The starting phase for pumps in water transportation pipelines is crucial and has significant transient characteristics which merit further study in order to evaluate the operational stability of the pumping system. This paper presents the results of a study in which the relative steady operating conditions and starting period of a large double-suction centrifugal pump were monitored in real time, including pressure fluctuations, shaft run-out and vibration at the bearing. The transient characteristics of a double-suction centrifugal pump under different operating conditions have been analyzed using fast Fourier transform (FFT) and continuous wavelet transform (CWT). Results indicate broadband Frequency components within the spectrum of pressure fluctuations in the volute casing under all test conditions, and the central Frequency of the broadband Frequency gradually decreases as flow rate increases and approaches the Blade Frequency, which is the primary reason for an increase in Blade-Frequency amplitude. This may produce a vibration Frequency that is similar to the natural Frequency of a certain part of the double-suction centrifugal pump during the starting period, which causes the resonance phenomenon. The radial force is also large during the starting period, which causes eccentric wear of the seal ring at the impeller inlet.

Zhifeng Yao - One of the best experts on this subject based on the ideXlab platform.

  • Experimental Investigation of Transient Characteristics of a Double Suction Centrifugal Pump System during Starting Period
    Energies, 2019
    Co-Authors: Faye Jin, Zhifeng Yao, Ruofu Xiao, Fujun Wang
    Abstract:

    The starting phase for pumps in water transportation pipelines is crucial and has significant transient characteristics which merit further study in order to evaluate the operational stability of the pumping system. This paper presents the results of a study in which the relative steady operating conditions and starting period of a large double-suction centrifugal pump were monitored in real time, including pressure fluctuations, shaft run-out and vibration at the bearing. The transient characteristics of a double-suction centrifugal pump under different operating conditions have been analyzed using fast Fourier transform (FFT) and continuous wavelet transform (CWT). Results indicate broadband Frequency components within the spectrum of pressure fluctuations in the volute casing under all test conditions, and the central Frequency of the broadband Frequency gradually decreases as flow rate increases and approaches the Blade Frequency, which is the primary reason for an increase in Blade-Frequency amplitude. This may produce a vibration Frequency that is similar to the natural Frequency of a certain part of the double-suction centrifugal pump during the starting period, which causes the resonance phenomenon. The radial force is also large during the starting period, which causes eccentric wear of the seal ring at the impeller inlet.

Ruofu Xiao - One of the best experts on this subject based on the ideXlab platform.

  • Experimental Investigation of Transient Characteristics of a Double Suction Centrifugal Pump System during Starting Period
    Energies, 2019
    Co-Authors: Faye Jin, Zhifeng Yao, Ruofu Xiao, Fujun Wang
    Abstract:

    The starting phase for pumps in water transportation pipelines is crucial and has significant transient characteristics which merit further study in order to evaluate the operational stability of the pumping system. This paper presents the results of a study in which the relative steady operating conditions and starting period of a large double-suction centrifugal pump were monitored in real time, including pressure fluctuations, shaft run-out and vibration at the bearing. The transient characteristics of a double-suction centrifugal pump under different operating conditions have been analyzed using fast Fourier transform (FFT) and continuous wavelet transform (CWT). Results indicate broadband Frequency components within the spectrum of pressure fluctuations in the volute casing under all test conditions, and the central Frequency of the broadband Frequency gradually decreases as flow rate increases and approaches the Blade Frequency, which is the primary reason for an increase in Blade-Frequency amplitude. This may produce a vibration Frequency that is similar to the natural Frequency of a certain part of the double-suction centrifugal pump during the starting period, which causes the resonance phenomenon. The radial force is also large during the starting period, which causes eccentric wear of the seal ring at the impeller inlet.

Steen Sverre - One of the best experts on this subject based on the ideXlab platform.

  • Time Domain Modeling of Propeller Forces due to Ventilation in Static and Dynamic Conditions
    'MDPI AG', 2020
    Co-Authors: Kozlowska, Anna Maria, Dalheim, Øyvind Øksnes, Savio Luca, Steen Sverre
    Abstract:

    This paper presents experimental and theoretical studies on the dynamic effect on the propeller loading due to ventilation by using a simulation model that generates a time domain solution for propeller forces in varying operational conditions. For ventilation modeling, the simulation model applies a formula based on the idea that the change in lift coefficient due to ventilation computes the change in the thrust coefficient. It is discussed how dynamic effects, like hysteresis effects and Blade Frequency dynamics, can be included in the simulation model. Simulation model validation was completed by comparison with CFD (computational fluid dynamics) calculations and model experiments. Experiments were performed for static and dynamic (heave motion) conditions in the large towing tank at the SINTEF Ocean in Trondheim and in the Marine Cybernetics Laboratories at NTNU (Norwegian University of Science and Technology). The main focus of this paper is to explain and validate the prediction model for thrust loss due to ventilation and out of water effects in static and dynamic heave conditions.publishedVersio

  • Time Domain Modeling of Propeller Forces due to Ventilation in Static and Dynamic Conditions
    'MDPI AG', 2020
    Co-Authors: Kozlowska, Anna Maria, Dalheim, Øyvind Øksnes, Savio Luca, Steen Sverre
    Abstract:

    This paper presents experimental and theoretical studies on the dynamic effect on the propeller loading due to ventilation by using a simulation model that generates a time domain solution for propeller forces in varying operational conditions. For ventilation modeling, the simulation model applies a formula based on the idea that the change in lift coefficient due to ventilation computes the change in the thrust coefficient. It is discussed how dynamic effects, like hysteresis effects and Blade Frequency dynamics, can be included in the simulation model. Simulation model validation was completed by comparison with CFD (computational fluid dynamics) calculations and model experiments. Experiments were performed for static and dynamic (heave motion) conditions in the large towing tank at the SINTEF Ocean in Trondheim and in the Marine Cybernetics Laboratories at NTNU (Norwegian University of Science and Technology). The main focus of this paper is to explain and validate the prediction model for thrust loss due to ventilation and out of water effects in static and dynamic heave conditions