Controllable velocity moment and prediction model for inlet guide vanes of a centrifugal pump

2018 ◽  
Vol 35 (3) ◽  
pp. 1364-1382 ◽  
Author(s):  
Ming Liu ◽  
Lei Tan ◽  
Yabin Liu ◽  
Yun Xu ◽  
Shuliang Cao
Keyword(s):  
Prediction Model ◽  
Centrifugal Pump ◽  
Flow Rate ◽  
Stokes Equations ◽  
Design Method ◽  
Three Dimensional ◽  
Guide Vanes ◽  
Content Type ◽  
Inlet Guide Vanes ◽  
Velocity Moment

Purpose This paper aims to investigate the effect of three-dimensional (3D) inlet guide vanes (IGVs) on performance of a centrifugal pump. Design/methodology/approach A design method for 3D IGVs is proposed based on the controllable velocity moment, which is determined by a fourth-order dimensionless function. Numerical simulation of the centrifugal pump with IGVs is carried out by solving the Reynolds-averaged Navier–Stokes equations. The method of frozen rotor is applied to couple the stationary and rotational domain. Findings The efficiency of pump with 3D IGVs is higher than that with 2D IGVs for most prewhirl angles, which validate the advancement of 3D IGVs on prewhirl regulation. The effect of prewhirl regulation at small flow rate is more significant than that at large flow rate. Originality/value A prediction model of velocity moment based on the Oseen vortex is proposed to describe the flow pattern downstream the IGVs.

Numerical investigation of clocking effect on a centrifugal pump with inlet guide vanes

2016 ◽  
Vol 33 (2) ◽  
Author(s):  
WANSHI QU ◽  
lei tan ◽  
Shuliang CAO ◽  
YUCHUAN WANG ◽  
YUN XU
Keyword(s):  
Flow Field ◽  
Numerical Investigation ◽  
Centrifugal Pump ◽  
Flow Rate ◽  
Pressure Fluctuation ◽  
Design Methodology ◽  
Design Flow ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
Design Flow Rate

Purpose The paper aims to investigate the clocking effect on a centrifugal pump with inlet guide vanes (IGVs). Design/methodology/approach The paper uses a computation fluid dynamics (CFD) framework to solve the unsteady flows in a centrifugal pump with inlet guide vanes. The relative position between the stationary vanes and the stationary volute tongue is defined as the clocking position when IGVs inside the suction pipe rotate along the circumferential direction. Findings The results show that clocking positions have little effect on the pump head and efficiency, however their influences are obvious for the pressure fluctuation and flow field in the centrifugal pump. The maximum difference of pressure amplitude at dominant frequency reach up to 28% on the monitoring point V8 at different clocking positions under design flow rate. For the large flow rate, the clocking effect on flow field and pressure fluctuation in centrifugal pump is similar to that of design flow rate. However, the clocking effect is nearly negligible at partial flow rate, because there are reverse flows around the tongue tip and obvious vortexes forming and developing in the impeller. Those complex phenomena interacting in the centrifugal pump make the clocking effect less evident. Originality/value The numerical investigation reveals the clocking effect on a centrifugal pump with inlet guide vanes, which also valuable for the stable operation and optimal design of centrifugal pumps.

Influence of Geometry of Inlet Guide Vanes on Pressure Fluctuations of a Centrifugal Pump

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Ming Liu ◽  
Lei Tan ◽  
Shuliang Cao
Keyword(s):  
Centrifugal Pump ◽  
Turbulence Model ◽  
Pressure Fluctuations ◽  
Three Dimensional ◽  
Maximum Amplitude ◽  
Dominant Frequency ◽  
Centrifugal Pumps ◽  
Maximum Increase ◽  
Guide Vanes ◽  
Inlet Guide Vanes

Prewhirl regulation by inlet guide vanes (IGVs) has been proven as an effective method for operation regulation of centrifugal pumps. By contrast, the influence of the geometry of IGVs on operation stability of centrifugal pump remains unknown. The pressure fluctuations and flow patterns in a centrifugal pump without and with two-dimensional (2D) or three-dimensional (3D) IGVs are investigated numerically at 1.0Qd, 0.6Qd, and 1.2Qd. Renormalization group (RNG) k–ε turbulence model is used as turbulence model, and fast Fourier transform (FFT) method is used to analyze the pressure fluctuations. The dominant frequency of pressure fluctuations in impellers is either the rotational frequency fi or twice thereof for pumps without and with IGVs at three flow rates, while the dominant frequency is constantly the blade passing frequency in volute. For 1.0Qd, the comparison of pumps without IGVs indicates that the maximum amplitude of pressure fluctuations at fi in pumps with 2D IGVs is decreased by an average of 22.2%, and the amplitude is decreased by an average of 44.9% in pumps with 3D IGVs. The IGVs mainly influence the pressure fluctuations at fi but indicate minimal influence at 2fi. For 0.6Qd, the comparison of pumps without IGVs denotes that the maximum amplitudes of pressure fluctuations at fi in pumps with 2D or 3D IGVs both increase; the maximum increase is 2.01%. For 1.2Qd, the comparison of pumps without IGVs indicates that the maximum amplitudes of pressure fluctuations at fi in pumps with 2D or 3D IGVs both decrease; the maximum decline is 15.9%.

Redesign of a Compressor Stage for a High-Performance Electric Supercharger in a Heavily Downsized Engine

2017 ◽  
Vol 140 (4) ◽  
Author(s):  
Peng Wang ◽  
Mehrdad Zangeneh ◽  
Bryn Richards ◽  
Kevin Gray ◽  
James Tran ◽  
...  
Keyword(s):  
Design Method ◽  
Pressure Ratio ◽  
Compressor Stage ◽  
Impeller Blade ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
Surge Margin ◽  
Stable Operating ◽  
Inverse Design Method ◽  
Ported Shroud

Engine downsizing is a modern solution for the reduction of CO2 emissions from internal combustion engines. This technology has been gaining increasing attention from industry. In order to enable a downsized engine to operate properly at low speed conditions, it is essential to have a compressor stage with very good surge margin. The ported shroud, also known as the casing treatment, is a conventional way used in turbochargers to widen the working range. However, the ported shroud works effectively only at pressure ratios higher than 3:1. At lower pressure ratio, its advantages for surge margin enhancements are very limited. The variable inlet guide vanes are also a solution to this problem. By adjusting the setting angles of variable inlet guide vanes, it is possible to shift the compressor map toward the smaller flow rates. However, this would also undermine the stage efficiency, require extra space for installing the inlet guide vanes, and add costs. The best solution is therefore to improve the design of impeller blade itself to attain high aerodynamic performances and wide operating ranges. This paper reports a recent study of using inverse design method for the redesign of a centrifugal compressor stage used in an electric supercharger, including the impeller blade and volute. The main requirements were to substantially increase the stable operating range of the compressor in order to meet the demands of the downsized engine. The three-dimensional (3D) inverse design method was used to optimize the impeller geometry and achieve higher efficiency and stable operating range. The predicted performance map shows great advantages when compared with the existing design. To validate the computational fluid dynamics (CFD) results, this new compressor stage has also been prototyped and tested. It will be shown that the CFD predictions have very good agreement with experiments and the redesigned compressor stage has improved the pressure ratio, aerodynamic efficiency, choke, and surge margins considerably.

scholarly journals Multiscale, thermomechanical topology optimization of self-supporting cellular structures for porous injection molds

2019 ◽  
Vol 25 (9) ◽  
pp. 1482-1492
Author(s):  
Tong Wu ◽  
Andres Tovar
Keyword(s):  
Topology Optimization ◽  
Mechanical Performance ◽  
Mechanical Load ◽  
Design Method ◽  
Three Dimensional ◽  
Optimization Method ◽  
Cellular Structures ◽  
Injection Mold ◽  
Computationally Efficient ◽  
Content Type

Purpose This paper aims to establish a multiscale topology optimization method for the optimal design of non-periodic, self-supporting cellular structures subjected to thermo-mechanical loads. The result is a hierarchically complex design that is thermally efficient, mechanically stable and suitable for additive manufacturing (AM). Design/methodology/approach The proposed method seeks to maximize thermo-mechanical performance at the macroscale in a conceptual design while obtaining maximum shear modulus for each unit cell at the mesoscale. Then, the macroscale performance is re-estimated, and the mesoscale design is updated until the macroscale performance is satisfied. Findings A two-dimensional Messerschmitt Bolkow Bolhm (MBB) beam withstanding thermo-mechanical load is presented to illustrate the proposed design method. Furthermore, the method is implemented to optimize a three-dimensional injection mold, which is successfully prototyped using 420 stainless steel infiltrated with bronze. Originality/value By developing a computationally efficient and manufacturing friendly inverse homogenization approach, the novel multiscale design could generate porous molds which can save up to 30 per cent material compared to their solid counterpart without decreasing thermo-mechanical performance. Practical implications This study is a useful tool for the designer in molding industries to reduce the cost of the injection mold and take full advantage of AM.

Design Optimization of Splitter Blade Impeller in a Centrifugal Pump

2020 ◽  
Author(s):  
Shunya Takao ◽  
Kentarou Hayashi ◽  
Masahiro Miyabe
Keyword(s):  
Centrifugal Pump ◽  
Flow Rate ◽  
Design Method ◽  
General Purpose ◽  
Stable Operation ◽  
Centrifugal Pumps ◽  
Unstable Flow ◽  
Rate Range ◽  
Flow Rate Range ◽  
Suction Performance

Abstract In order to improve suction performance, centrifugal pumps with an inducer are used for rocket pumps, liquid gas transport such as LNG, and general-purpose pumps. Since a higher suction performance than conventional pump is required, a splitter blade that consists of a long blade and a short blade is sometimes adopted. However, the design becomes more difficult due to the increased number of parameters. The stable operation over a wide flow rate range are required in the general-purpose pumps. Therefore it is necessary to design them so that unstable flow phenomena such as surges do not occur. However, the design method to avoid them is not well understood yet. In this study, we focused on the splitter blade impeller in a general-purpose low-speed centrifugal pump with an inducer. Six parameters such as leading edge position and trailing edge position of the short blade for both hub-side and tip-side were set as design ones. A multi-objective optimization method using a commercial software was applied to improve suction performance while maintaining high efficiency. Then obtained optimal shape were analyzed by CFD calculation and extracted the feature. Furthermore, optimized impellers were manufactured and confirmed the performance over a wide flow rate range by experiments. In addition, a optimizing design method that improves pump performance at lower cost was studied.

Numerical study on instantaneous radial force of a centrifugal pump for different working conditions

2019 ◽  
Vol 37 (2) ◽  
pp. 458-480
Author(s):  
Xiaoqi Jia ◽  
Sheng Yuan ◽  
Zuchao Zhu ◽  
Baoling Cui
Keyword(s):  
Numerical Simulation ◽  
Unsteady Flow ◽  
Centrifugal Pump ◽  
Working Conditions ◽  
Flow Rate ◽  
Pressure Pulsation ◽  
Radial Force ◽  
Leakage Rate ◽  
Content Type ◽  
Three Components

Purpose Instantaneous radial force induced from unsteady flow will intensify vibration noise of the centrifugal pump, especially under off-design working conditions, which will affect safety reliability of pump operation in severe cases. This paper aims to conduct unsteady numerical computation on one centrifugal pump; thus, unsteady fluid radial force upon the impeller and volute is obtained, so as to study the evolution law of instantaneous radial force, the internal relationship between radial force and pressure pulsation, the relationship among each composition of radial force that the impeller received and the influence of leakage rate of front and back chamber on radial force. Design/methodology/approach The unsteady numerical simulation with SST k-ω turbulence model was carried out for a low specific-speed centrifugal pump using computational fluid dynamics codes FLUENT. The performance tests and pressure tests were conducted by a closed loop system. The performance curves and the pressure distribution from numerical simulation agree with that of the experiment conducted. The unsteady pressure distributions and the instantaneous radial forces induced from unsteady flow were analyzed under different flow rates. Contribution degrees of three components of the radial force on the impeller and the relation between the radial force and leakage rate were analyzed. Findings Radial force on the volute and pressure pulsation on the volute wall have the same distribution tendency, but in contrast to the distribution trend of the radial force on the impeller. In the component of radial force that the impeller received, radial force on the blade accounts for the main position. With the decrease of flow rate, ratio of the radial force on front and back casings will be increased; under large flow rate, vortex and flow blockage at volute section will enhance the pressure and radial force fluctuation greatly, and the pulsation degree may be much more intense than that of a smaller flow rate. Originality/value This paper revealed the relation of the radial force and the pressure pulsation. Meanwhile, contribution degrees of three components of the radial force on the impeller under different working conditions as well as the relation between the radial force and leakage rate of front and rear chambers were analyzed.

The Research on Numerical Simulation of the Centrifugal Pump and Configuration Perfected

2013 ◽  
Vol 694-697 ◽  
pp. 56-60
Author(s):  
Yue Jun Ma ◽  
Ji Tao Zhao ◽  
Yu Min Yang
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Pump ◽  
Unstructured Grid ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Internal Flow ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Flow Phenomena ◽  
Simplec Algorithm

In the paper, on the basis of three-dimensional Reynolds-averaged Navier-Stokes equations and the RNG κ-ε turbulence model, adopting Three-dimensional unstructured grid and pressure connection the implicit correction SIMPLEC algorithm, and using MRF model which is supported by Fluent, this paper carries out numerical simulation of the internal flow of the centrifugal pump in different operation points. According to the results of numerical simulation, this paper analyzes the bad flow phenomena of the centrifugal pump, and puts forward suggests about configuration perfected of the centrifugal pump. In addition, this paper is also predicted the experimental value of the centrifugal pump performance, which is corresponding well with the measured value.

scholarly journals Aerothermodynamic Effects and Modeling of the Tangential Curvature of Guide Vanes in an Axial Turbine Stage

2017 ◽  
Vol 2017 ◽  
pp. 1-16
Author(s):  
Tzong-Hann Shieh
Keyword(s):  
Stokes Equations ◽  
Three Dimensional ◽  
Suction Side ◽  
Meridional Flow ◽  
Navier Stokes ◽  
Obtuse Angle ◽  
Turbine Stage ◽  
Navier Stokes Equations ◽  
Axial Turbine ◽  
Guide Vanes

By tangential curvature of the stacking line of the profiles guide vanes can be designed, which have on both ends an obtuse angle between suction side and sidewall. This configuration, according to literature, is capable of reducing secondary loss. This type of vanes develops considerable radial components of the blade force and effects a displacement of the meridional flow towards both sidewalls. In this paper we work with a finite-volume-code for computations of the three-dimensional Reynolds averaged Navier-Stokes equations for an axial turbine stage with radial and two types of tangentially curved guide vanes. With computational results, mathematical formulations are developed for a new flow model of deflection of such blades that are formally compatible with the assumption of a rotation-symmetrical flow and with the existing throughflow codes, in order to predict the deflection angle over the blade height for the tangential leaned and curved blades.

The effect of wear ring clearance on flow field in the impeller sidewall gap and efficiency of a low specific speed centrifugal pump

2017 ◽  
Vol 232 (17) ◽  
pp. 3062-3073 ◽  
Author(s):  
M DaqiqShirazi ◽  
R Torabi ◽  
A Riasi ◽  
SA Nourbakhsh
Keyword(s):  
Flow Field ◽  
Centrifugal Pump ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Volumetric Efficiency ◽  
Centrifugal Pumps ◽  
Disk Friction ◽  
Low Specific Speed ◽  
Overall Efficiency ◽  
Specific Speed

In this paper, the flow in the impeller sidewall gap of a low specific speed centrifugal pump is analyzed to study the effect of wear ring clearance and the resultant through-flow on flow field in this cavity and investigate the overall efficiency of the pump. Centrifugal pumps are commonly subject to a reduction in the flow rate and volumetric efficiency due to abrasive liquids or working conditions, since the wear rings are progressively worn, the internal leakage flow is increased. In the new operating point, the overall efficiency of the pump cannot be predicted simply by using the pump characteristic curves. The flow field is simulated with the use of computational fluid dynamics and the three-dimensional full Navier–Stokes equations are solved using CFX software. In order to verify the numerical simulations, static pressure field in volute casing and pump performance curves are compared with the experimental measurements. The results show that, for the pump with minimum wear ring clearance, the disk friction efficiency is the strongest factor that impairs the overall efficiency. Therefore, when the ring clearance is enlarged more than three times, although volumetric efficiency decreases effectively but the reduction in overall efficiency is remarkably smaller due to improvement in the disk friction losses.

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