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

  • Effects of the Impeller Blade with a Slot Structure on the Centrifugal Pump Performance
    Energies, 2020
    Co-Authors: Hongliang Wang, Chuan Wang, Bing Long, Chen Han
    Abstract:

    An Impeller Blade with a slot structure can affect the velocity distribution in the Impeller flow passage of the centrifugal pump, thus affecting the pump’s performance. Various slot structure geometric parameter combinations were tested in this study to explore this relationship: slot position p, slot width b1, slot deflection angle β, and slot depth h with (3–4) levels were selected for each factor on an L16 orthogonal test table. The results show that b1 and h are the major factors influencing pump performance under low and rated flow conditions, while p is the major influencing factor under the large flow condition. The slot structure close to the front edge of the Impeller Blade can change the low-pressure region of the suction inlet of the Impeller flow passage, thus improving the fluid velocity distribution in the Impeller. Optimal slot parameter combinations according to the actual machining precision may include a small slot width b1, slot depth h of ¼ b, slot deflection angle β of 45°–60°, and slot position p close to the front edge of the Blade at 20–40%.

  • numerical study on pressure fluctuation of a multistage centrifugal pump based on whole flow field
    AIP Advances, 2019
    Co-Authors: Chuan Wang, Xiaoke He, Xikun Wang, Xiuli Wang
    Abstract:

    Multistage centrifugal pumps can provide high-pressure fluid flow, and is widely used in various engineering applications. However, the pressure fluctuation in the pumps strongly affects the flow and pressure stability. To gain further insight into the pressure fluctuation of multistage centrifugal pumps, a numerical model of a typical multistage centrifugal pump model was constructed and the flow investigated systematically under different operating conditions. Changes in amplitude, frequency, and phase of pressure fluctuation in the Impellers, diffusers, and pump cavities were observed and analyzed in both time-domain and frequency-domain. The pressure fluctuations of the fluid in the Impeller were found to originate from the inlet side of the outward diffuser, whereas that in the diffuser arose from the outlet side of the Impeller Blade. In contrast, the pressure fluctuations in the pump cavity were initiated from the outlet side of the Impeller Blade and the interstage leakage of fluid. This study also conclude that the pressure fluctuations are essentially a wave with identifiable amplitude, frequency, and phase.Multistage centrifugal pumps can provide high-pressure fluid flow, and is widely used in various engineering applications. However, the pressure fluctuation in the pumps strongly affects the flow and pressure stability. To gain further insight into the pressure fluctuation of multistage centrifugal pumps, a numerical model of a typical multistage centrifugal pump model was constructed and the flow investigated systematically under different operating conditions. Changes in amplitude, frequency, and phase of pressure fluctuation in the Impellers, diffusers, and pump cavities were observed and analyzed in both time-domain and frequency-domain. The pressure fluctuations of the fluid in the Impeller were found to originate from the inlet side of the outward diffuser, whereas that in the diffuser arose from the outlet side of the Impeller Blade. In contrast, the pressure fluctuations in the pump cavity were initiated from the outlet side of the Impeller Blade and the interstage leakage of fluid. This study als...

  • numerical study on pressure fluctuation of a multistage centrifugal pump based on whole flow field
    AIP Advances, 2019
    Co-Authors: Chuan Wang, Weidong Shi, Xikun Wang, Xiuli Wang, Ning Qiu
    Abstract:

    Multistage centrifugal pumps can provide high-pressure fluid flow, and is widely used in various engineering applications. However, the pressure fluctuation in the pumps strongly affects the flow and pressure stability. To gain further insight into the pressure fluctuation of multistage centrifugal pumps, a numerical model of a typical multistage centrifugal pump model was constructed and the flow investigated systematically under different operating conditions. Changes in amplitude, frequency, and phase of pressure fluctuation in the Impellers, diffusers, and pump cavities were observed and analyzed in both time-domain and frequency-domain. The pressure fluctuations of the fluid in the Impeller were found to originate from the inlet side of the outward diffuser, whereas that in the diffuser arose from the outlet side of the Impeller Blade. In contrast, the pressure fluctuations in the pump cavity were initiated from the outlet side of the Impeller Blade and the interstage leakage of fluid. This study also conclude that the pressure fluctuations are essentially a wave with identifiable amplitude, frequency, and phase.

  • Numerical calculation and finite element calculation on Impeller of stainless steel multistage centrifugal pump
    Journal of Vibroengineering, 2014
    Co-Authors: Chuan Wang, Weidong Shi, Si Qiaorui, Ling Zhou
    Abstract:

    In order to save energy and materials, some mechanical structures are very thin. Aiming to study the influence of Impeller Blade thickness on the performance of stainless steel multistage centrifugal pump, the whole flow field of stainless steel multistage centrifugal pump with different Blade thickness were calculated based on ANSYS Fluent. The relationship between the Impeller Blade thickness and the overall performance of the pump was analyzed. To further study the reliability of the Impeller structure for stainless steel multistage centrifugal pump, based on the ANSYS Workbench, the final stage Impeller of the pump with different Blade thickness were calculated by using the finite element method. Results indicate that with the increase of Blade thickness, the maximum stress and deformation of the Impeller gradually decreased, while the stability of the Impeller structure increased.

  • Effect Analysis of Geometric Parameters on Stainless Steel Stamping Multistage Pump by Experimental Test and Numerical Calculation
    Advances in Mechanical Engineering, 2013
    Co-Authors: Chuan Wang, Weidong Shi, Ling Zhou
    Abstract:

    In order to improve the efficiency of stainless steel stamping multistage pump, quadratic regression orthogonal test, hydraulic design, and computational fluid dynamics (CFD) are used to analyze the effect of pump geometric parameters. Sixteen Impellers are designed based on the quadratic regression orthogonal test, which have three factors including Impeller outlet slope, Impeller Blade outlet stagger angle, and Impeller Blade outlet width. Through quadratic regression equation, the function relationship between efficiency values and three factors is established. The optimal combination of geometric parameters is found through the analysis of the regression equation. To further study the influence of Blade thickness on the performance of multistage pump, numerical simulations of multistage pump with different Blade thicknesses are carried out. The influence law of Blade thickness on pump performance is built from the external characteristics and internal flow field. In conclusion, with the increase of bl...

Donald Rockwell - One of the best experts on this subject based on the ideXlab platform.

  • Interaction of zones of flow separation in a centrifugal Impeller-stationary vane system
    Experiments in Fluids, 1994
    Co-Authors: O. Akin, Donald Rockwell
    Abstract:

    In a radial flow pump operating in off-design conditions, regions of stall can exist on the rotating Impeller Blade and on the downstream diffuser Blade, vane or tongue. Interaction of these stall zones can generate complex patterns of vorticity concentrations. In turn, these vorticity concentrations are related to sources of unsteady stagnation enthalpy. The form of these patterns is strongly dependent on the instantaneous location of the Impeller trailing-edge relative to the leading-edge of the vane. Comparison of instantaneous with ensemble-averaged images shows that the flow structure in the gap region between the Impeller and the vane is highly repetitive. Away from this region, in particular in the separated shear layer from the vane, the nonrepetitive nature of the vorticity field is manifested in substantial reduction of peak levels of vorticity in the ensemble-averaged image, relative to the instantaneous image. The three-dimensional flow structure resulting from these separation zone interactions was characterized via end views of the flow patterns. Particularly pronounced concentrations of vorticity can occur in this plane. They tend to be located in the shear layer at the outer edge of the large-scale separation zone. These vorticity concentrations are, however, highly non-stationary for successive passages of the Impeller Blade. Ensemble-averaging reveals that they persist primarily on the endwalls of the diffuser.

  • Interaction of zones of flow separation in a centrifugal Impeller-stationary vane system
    Experiments in Fluids, 1994
    Co-Authors: O. Akin, Donald Rockwell
    Abstract:

    In a radial flow pump operating in off-design conditions, regions of stall can exist on the rotating Impeller Blade and on the downstream diffuser Blade, vane or tongue. Interaction of these stall zones can generate complex patterns of vorticity concentrations. In turn, these vorticity concentrations are related to sources of unsteady stagnation enthalpy. The form of these patterns is strongly dependent on the instantaneous location of the Impeller trailing-edge relative to the leading-edge of the vane.

Elisabetta Brunazzi - One of the best experts on this subject based on the ideXlab platform.

  • Effect of shaft eccentricity and Impeller Blade thickness on the vortices features in an unbaffled vessel
    Chemical Engineering Research and Design, 2009
    Co-Authors: Chiara Galletti, Sandro Pintus, Elisabetta Brunazzi
    Abstract:

    Abstract Different techniques, i.e. laser Doppler anemometry, flow visualisation and decolourisation, were applied in order to gain insight into the main turbulent flow features of an unbaffled vessel stirred by an eccentrically positioned Rushton turbine. Attention was paid to the effect of geometrical parameters such as eccentricity and Impeller Blade thickness on the flow motion. Two main vortices, one above and one below the Impeller, were identified in all configurations. Decolourisation experiments showed that the two vortices behave as segregated regions. The upper vortex dominates the flow field, driving a strong circumferential flow around it. The inclination of such vortex varies with eccentricity. Importantly, the vortex is not steady but oscillates slowly and periodically inducing a kind of flow instabilities, which may have a significant impact on macro-mixing. The characteristic frequency of flow instabilities was found to increase with reducing eccentricity or Impeller Blade thickness. Moreover, vortex shedding phenomena from the flow–shaft interaction were observed in different configurations.

Abraham Engeda - One of the best experts on this subject based on the ideXlab platform.

  • Performance impact of Impeller Blade trimming on centrifugal compressors
    Proceedings of the Institution of Mechanical Engineers Part A: Journal of Power and Energy, 2014
    Co-Authors: Daniel Swain, Abraham Engeda
    Abstract:

    Centrifugal Impeller Blade trimming can be used to modify an existing Impeller design to meet a new flow or pressure ratio design point. In flow trimming, the passage area is reduced from inlet to outlet along the entire meridional length of the Impeller to reduce the flow coefficient of the Impeller while maintaining the pressure ratio of the untrimmed Impeller. Axial trimming is a method of reducing the Blade height at the Impeller exit while maintaining the shroud profile of the original Impeller in order to reduce the head coefficient of the Impeller while maintaining the original flow range. In this work, computational fluid dynamics was employed to numerically model four Impellers of varying geometries, speeds, and performance characteristics to study the performance effects and limits of modifying the Impeller geometry by either flow or axial trimming. Flow trimming was found to be capable of reducing the flow coefficient by between 20 and 50% while maintaining the pressure ratio and efficiency of ...

  • effect of Impeller Blade trimming on the performance of a 5 5 1 pressure ratio centrifugal compressor
    Proceedings of the Institution of Mechanical Engineers Part A: Journal of Power and Energy, 2014
    Co-Authors: Daniel Swain, Abraham Engeda
    Abstract:

    Centrifugal compressor Blade trimming can be used for the purpose of changing the performance characteristics of an Impeller or allowing a single Impeller design to be used for a range of operating conditions. There are different methods of Impeller Blade trimming that may be employed to change the Impeller flow rate, the pressure ratio, or both. In this study, computational fluid dynamics is used to model the effects of two different methods of Blade trimming on a single centrifugal compressor design. Impeller performance characteristics and analysis of the flow field are presented for a series of trims. Trimming the passage area from inlet to outlet along the meridional length reduced the flow rate of the Impeller and narrowed the effective operating range. The head coefficient and efficiency relative to the choked flow coefficient remained unchanged as the passage area is reduced; however, the flow rate is reduced by a greater amount than the inlet area is reduced. Trimming the Impeller Blades by shift...

  • effect of Impeller Blade trimming on the performance of a 5 5 1 pressure ratio centrifugal compressor
    ASME 2012 Gas Turbine India Conference GTINDIA 2012, 2012
    Co-Authors: Daniel Swain, Abraham Engeda
    Abstract:

    Centrifugal compressor Blade trimming can be used for the purpose of changing the performance characteristics of an Impeller or allowing a single Impeller design to be used for a range of operating conditions. There are a number of methods of Impeller Blade trimming that may be employed to change the Impeller flowrate, the pressure ratio, or both; however, the limitations of Blade trimming and the effect on the flow field are not well understood.In this study, CFD is used to model the effects of three different methods of Blade trimming on a single centrifugal compressor design. Impeller performance characteristics and analysis of the flow field are presented for a series of trims for each of the three trimming methods.Each method of trimming was found to be limited at some point by choke. Shifting the original shroud profile both axially and radially in proportion to the desired flow coefficient allowed the pressure ratio and efficiency of the original Impeller to be maintained while changing the flow coefficient. Trimming the Blades along the meridional length in proportion to the desired new flow coefficient without regard to the original shroud profile produced similar results, but allowed the Impeller to be trimmed further than was practical using the radial-axial shroud offset method. Trimming the Blades axially so that the original shroud profile is maintained produced a change in pressure ratio while maintaining the original Impeller flow coefficient.Copyright © 2012 by ASME

Michael Yianneskis - One of the best experts on this subject based on the ideXlab platform.

  • the influence of rushton Impeller Blade and disk thickness on the mixing characteristics of stirred vessels
    Chemical Engineering Research & Design, 1996
    Co-Authors: K Rutherford, S M S Mahmoudi, K C Lee, Michael Yianneskis
    Abstract:

    The influence of Impeller Blade and disk thickness on the mixing characteristics of stirred vessels operating with a single Rushton Impeller have been investigated. Laser Doppler anemometry (LDA) measurements of the mean and fluctuating velocities, ensemble-averaged over both 360° of Impeller revolution and between a specific Impeller Blade pair (over 60°), were performed in vessels of diameter (T) 100 mm and 294 mm in order to characterize the flow in the Impeller vicinity and to assess the effect of vessel scale. The velocity profiles are presented and flow numbers (Fl) are calculated, which show Fl to decrease by up to 15% as the ratio of Impeller Blade and disk thickness (t) to diameter (D), was increased from 0.008 to 0.033. Torque measurements performed using a telemetric strain gauge arrangement showed a reduction in Impeller power number (Po) by up to 33%, with a similar increase in Impeller thickness ratio, while the mixing time (t M ) increased by around 15% with increasing t/D. The effects of t/D on the mean and fluctuating velocity components in the two vessels are also reported and the influence of vessel scale on the flow characteristics is assessed.