Centrifugal Pump Impeller with Forward Curved Blades for High Air-Water Two-phase Flow Performance and Unstable Phenomenon in Single-phase Flow

Water single-phase and nucleate boiling heat transfer were experimentally investigated in vertical annuli with narrow gaps. The experimental data about water single-phase flow and boiling two-phase flow heat transfer in narrow annular channel were accumulated by two test sections with the narrow gaps of 1.0mm and 1.5mm. Empirical correlations to predict the heat transfer of the single-phase flow and boiling two-phase flow in the narrow annular channel were obtained, which were arranged in the forms of the Dittus-Boelter for heat transfer coefficients in a single-phase flow and the Jens-Lottes formula for a boiling two-phase flow in normal tubes, respectively. The mechanism of the difference between the normal channel and narrow annular channel were also explored. From experimental results, it was found that the turbulent heat transfer coefficients in narrow gaps are nearly the same to the normal channel in the experimental range, and the transition Reynolds number from a laminar flow to a turbulent flow in narrow annuli was much lower than that in normal channel, whereas the boiling heat transfer in narrow annular gap was greatly enhanced compared with the normal channel.

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Transition of the electrohydrodynamic two-phase flow into the single-phase flow in a needle-to-plate negative corona discharge in the finite-volume chamber

Journal of Electrostatics ◽

10.1016/j.elstat.2016.09.007 ◽

2016 ◽

Vol 84 ◽

pp. 90-96 ◽

Cited By ~ 10

Author(s):

A. Berendt ◽

J. Mizeraczyk

Keyword(s):

Corona Discharge ◽

Finite Volume ◽

Single Phase ◽

Two Phase Flow ◽

Phase Flow ◽

Single Phase Flow ◽

Negative Corona ◽

Two Phase ◽

Negative Corona Discharge

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Turbulence Structure of a Liquid-Solid Two-Phase Jet by Means of Laser Techniques

Volume 1: Fora, Parts A, B, C, and D ◽

10.1115/fedsm2003-45495 ◽

2003 ◽

Cited By ~ 3

Author(s):

Toshimichi Arai ◽

Naoki Kudo ◽

Tsuneaki Ishima ◽

Ismail M. Youssef ◽

Tomio Obokata ◽

...

Keyword(s):

Particle Size ◽

Single Phase ◽

Two Phase Flow ◽

Volume Ratio ◽

Water Phase ◽

Phase Flow ◽

Size Discrimination ◽

Single Phase Flow ◽

Particle Volume ◽

Two Phase

Characteristics on particle motion in a liquid-solid two-phase jet flow were studied in the paper. The water jet including glass particle of 389 μm in mean diameter was injected into water bath. The experimental conditions were 0.21% of initial particle volume ratio, 5mm in pipe diameter and 1.84 m/s of mean velocity on outlet of the jet. A laser Doppler anemometer (LDA) with size discrimination was applied for measuring the time serious velocities of the single-phase flow, particle and water phase flow. A particle image velocimetry (PIV) was also applied in the two-phase flow. The normal PIV method can hardly measure the particle size and perform the particle size discrimination. In the experiment, using the gray scales related with the scattering light intensity, measuring method with size discrimination in two-phase flow was carried out. The experimental results show less difference between velocities of single-phase flow and water-phase flow under this low particle volume ratio condition. Particles have the relative motion with the water-phase and large rms velocity. The PIV used in this experiment, which is called multi-intensity-layer-PIV: MILP, can measure water-phase velocity with good accuracy.

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Research on Two-Phase Flow Induced Vibration Characteristics of U-Tube Bundles

Volume 4: Fluid-Structure Interaction ◽

10.1115/pvp2017-65207 ◽

2017 ◽

Cited By ~ 1

Author(s):

Jiang Nai-bin ◽

Gao Li-xia ◽

Huang Xuan ◽

Zang Feng-gang ◽

Xiong Fu-rui

Keyword(s):

Upper Bound ◽

Single Phase ◽

Two Phase Flow ◽

Tube Bundle ◽

Upper Bounds ◽

Vibration Response ◽

Phase Flow ◽

Single Phase Flow ◽

Two Phase ◽

Tube Bundles

In steam generators and other heat exchangers, there are a lot of tube bundles subjected to two-phase cross-flow. The fluctuating pressure on tube bundle caused by turbulence can induce structural vibration. The experimental data from a U-tube bundle of steam generator in air-water flow loop are analyzed in this work. The different upper bounds of buffeting force are used to calculate the turbulence buffeting response of U-tubes, and the calculation results are compared with the experimental results. The upper bounds of buffeting force include one upper bound based on single-phase flow, and two upper bounds based on two-phase flow. It is shown that the upper bound based on single-phase flow seriously underestimated the turbulence excitation, the calculated vibration response is much less than the experimental measurement. On the other hand, the vibration response results calculated with the upper bounds based on two-phase flow are closer to the measured results under most circumstances.

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