Numerical investigation of influence of the clocking effect on the unsteady pressure fluctuations and radial forces in the centrifugal pump with vaned diffuser

2016 ◽  
Vol 71 ◽  
pp. 164-171 ◽  
Author(s):  
Wei Jiang ◽  
Guojun Li ◽  
Peng-fei Liu ◽  
Lei Fu
Keyword(s):  
Numerical Investigation ◽  
Centrifugal Pump ◽  
Pressure Fluctuations ◽  
Vaned Diffuser ◽  
Unsteady Pressure ◽  
Radial Forces

Unsteady Flow Structure on a Centrifugal Pump: Experimental and Numerical Approaches

2002 ◽  
Author(s):  
Jose´ Gonza´lez ◽  
Carlos Santolaria ◽  
Eduardo Blanco ◽  
Joaqui´n Ferna´ndez
Keyword(s):  
Numerical Model ◽  
Centrifugal Pump ◽  
Pressure Field ◽  
Pressure Fluctuations ◽  
Side Wall ◽  
Relative Effect ◽  
Pressure Transducers ◽  
Unsteady Pressure ◽  
Blade Passing Frequency ◽  
Wide Range

Both experimental and numerical studies of the unsteady pressure field inside a centrifugal pump have been carried out. The unsteady patterns found for the pressure fluctuations are compared and a further and more detailed flow study from the numerical model developed will be presented in this paper. Measurements were carried out with pressure transducers installed on the volute shroud. At the same time, the unsteady pressure field inside the volute of a centrifugal pump has been numerically modelled using a finite volume commercial code and the dynamic variables obtained have been compared with the experimental data available. In particular, the amplitude of the fluctuating pressure field in the shroud side wall of the volute at the blade passing frequency is successfully captured by the model for a wide range of operating flow rates. Once the developed numerical model has shown its capability in describing the unsteady patterns experimentally measured, an explanation for such patterns is searched. Moreover, the possibilities of the numerical model can be extended to other sections (besides the shroud wall of the volute), which can provide plausible explanations for the dynamic interaction effects between the flow at the impeller exit and the volute tongue at different axial positions. The results of the numerical simulation are focused in the blade passing frequency in order to study the relative effect of the two main phenomena occurring at that frequency for a given position: the blade passing in front of the tongue and the wakes of the blades.

Investigation of Unsteady Pressure Fluctuations and Methods for Its Suppression for a Double Suction Centrifugal Pump

2021 ◽  
Author(s):  
Arihant Sonawat ◽  
Sang-Bum Ma ◽  
Seung-Jun Kim ◽  
Ju Beak Lee ◽  
Myo Suk Yu ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
Pressure Fluctuations ◽  
Unsteady Pressure

Numerical Study of Unsteady Flow in a Centrifugal Pump

2005 ◽  
Vol 127 (2) ◽  
pp. 363-371 ◽  
Author(s):  
Kitano Majidi
Keyword(s):  
Pressure Distribution ◽  
Centrifugal Pump ◽  
Numerical Study ◽  
Pressure Fluctuations ◽  
Three Dimensional ◽  
Reduced Pressure ◽  
Sliding Mesh ◽  
Unsteady Pressure ◽  
Impeller Outlet ◽  
Multiple Frame

Computational fluid dynamics (CFD) analysis has been used to solve the unsteady three-dimensional viscous flow in the entire impeller and volute casing of a centrifugal pump. The results of the calculations are used to predict the impeller/volute interaction and to obtain the unsteady pressure distribution in the impeller and volute casing. The calculated unsteady pressure distribution is used to determine the unsteady blade loading. The calculations at the design point and at two off-design points are carried out with a multiple frame of reference and a sliding mesh technique is applied to consider the impeller/volute interaction. The results obtained show that the flow in the impeller and volute casing is periodically unsteady and confirm the circumferential distortion of the pressure distribution at the impeller outlet and in the volute casing. Due to the interaction between impeller blades and the tongue of the volute casing the flow is characterized by pressure fluctuations, which are strong at the impeller outlet and in the vicinity of the tongue. These pressure fluctuations are died away in the casing as the advancement angle increases. These reduced pressure fluctuations are spread to the discharge nozzle; the pressure fluctuations are also reflected to the impeller inlet and they affect the mass flow rate through the blade passages.

Fundamental Analysis on Rotor-Stator Interaction in a Diffuser Pump by Vortex Method

2001 ◽  
Vol 123 (4) ◽  
pp. 737-747 ◽  
Author(s):  
H. Wang ◽  
H. Tsukamoto
Keyword(s):  
Numerical Solutions ◽  
Pressure Fluctuations ◽  
Vortex Method ◽  
Solid Boundary ◽  
Vaned Diffuser ◽  
Unsteady Pressure ◽  
Pumping System ◽  
Rotor Stator Interaction ◽  
The Stability ◽  
Stability And Accuracy

A two-dimensional unsteady flow was calculated within a whole stage of a diffuser pump to investigate pressure fluctuations due to the interaction between impeller and diffuser vanes by using the vortex method, in which vortices shedding from solid boundary were determined by the basic governing equation. The Petrov-Galerkin Method was applied to yield the solutions that satisfy the boundary conditions in an integral sense, and it improved the stability and accuracy of the numerical solutions greatly. A new scheme was also proposed to improve the unsteady pressure evaluation by a boundary integration method in the rotor-stator interaction problem. Moreover, for a more realistic prediction of the pressure fluctuations, the inlet flow was supposed to change with time so that pumping system may balance. The calculated time-varying flow rate, total hydraulic head rise and pressure fluctuations in the vaned diffuser passage, were compared with the measured and calculated ones by other methods. Calculated unsteady pressure fluctuations in the vaned diffuser passage showed good agreement with the experimental data and the CFD calculated ones.

Numerical Study of Unsteady Flow in a Centrifugal Pump

2004 ◽  
Author(s):  
Kitano Majidi
Keyword(s):  
Pressure Distribution ◽  
Centrifugal Pump ◽  
Numerical Study ◽  
Pressure Fluctuations ◽  
Three Dimensional ◽  
Reduced Pressure ◽  
Unsteady Pressure ◽  
Impeller Outlet ◽  
Computational Fluid Dynamics Analysis ◽  
Multiple Frame

Computational Fluid Dynamics analysis has been used to solve the unsteady three-dimensional viscous flow in the entire impeller and volute casing of a centrifugal pump. The results of the calculations are used to predict the impeller/volute interaction and to obtain the unsteady pressure distribution in the impeller and volute casing. The calculated unsteady pressure distribution is used to determine the unsteady blade loading. The calculations at the design point and at two off-design points are carried out with a multiple frame of reference and a sliding mesh technique is applied to consider the impeller/volute interaction. The results obtained show that the flow in the impeller and volute casing is periodically unsteady and confirm the circumferential distortion of the pressure distribution at the impeller outlet and in the volute casing. Due to the interaction between impeller blades and the tongue of the volute casing the flow is characterized by pressure fluctuations, which are strong at the impeller outlet and in the vicinity of the tongue. These pressure fluctuations are died away in the casing as the advancement angle increases. These reduced pressure fluctuations are spread to the discharge nozzle; the pressure fluctuations are also reflected to the impeller inlet and they affect the mass flow rate through the blade passages.

scholarly journals Pressure Fluctuation in a Vaned Diffuser Downstream from a Centrifugal Pump Impeller

2003 ◽  
Vol 9 (4) ◽  
pp. 285-292 ◽  
Author(s):  
Akinori Furukawa ◽  
Hisasada Takahara ◽  
Takahiro Nakagawa ◽  
Yusuke Ono
Keyword(s):  
Centrifugal Pump ◽  
Static Pressure ◽  
Pressure Fluctuations ◽  
Flow Analysis ◽  
Inviscid Flow ◽  
Blade Surface ◽  
Pump Impeller ◽  
Vaned Diffuser ◽  
Singularity Method ◽  
Centrifugal Pump Impeller

Periodic flows downstream from a centrifugal pump impeller in vaneless and vaned diffusers were measured by using a single hole yawmeter and a phase-locked sampling method. The flows were also calculated by an inviscid flow analysis using the blade-surface singularity method. The periodic variations in calculated static pressure with the impeller rotating quantitatively agree well with the measured ones. The flow behaviors in the vaned diffuser are discussed, citing measured and calculated results. The potential interaction between the impeller and the diffuser blades appears more strongly than the impeller-wake interaction. The appearance of static pressure fluctuations due to the impeller's rotating in the fully vaned zone is different from that in the semivaned zone of the diffuser. The existence of the peripheral blade surface of the impeller outlet with an outlet edge of the pressure surface causes violent pressure fluctuations in the vaned diffuser.

Experimental and Numerical Investigation of a Centrifugal Pump Working as a Turbine

2009 ◽  
Author(s):  
Joaqui´n Ferna´ndez ◽  
Rau´l Barrio ◽  
Eduardo Blanco ◽  
Jorge Parrondo ◽  
Alfonso Marcos
Keyword(s):  
Numerical Investigation ◽  
Centrifugal Pump ◽  
Static Pressure ◽  
Maximum Amplitude ◽  
Radial Force ◽  
Local Flow ◽  
Sliding Mesh ◽  
Static Pressure Distribution ◽  
Numerical Predictions ◽  
Radial Forces

An experimental and numerical investigation of a conventional centrifugal pump working as a turbine is presented. The numerical simulations were performed with the code Fluent by means of unsteady flow calculations and a sliding mesh technique to account for the impeller-volute interactions. Thus, it was possible to properly simulate the effect on the local flow of the passage of the impeller blades in front of the volute tongue. The numerical results were compared with the experimentally determined performance curves and additionally with the static pressure distribution measured around the impeller periphery. Once validated, the model was used to estimate the steady and unsteady radial forces on the impeller for a number of flow rates. The steady radial force was also experimentally estimated from the static pressure measurements around the periphery of the impeller. The numerical predictions showed that, for the flow interval considered in the present investigation, the unsteady radial force varied between 24% and 54.3% of the steady magnitude, and that its maximum amplitude was reached when the trailing edge of one of the blades was located 3 deg downstream the tip of the tongue.

Effects of Lean Mode of Blade Trailing Edge On Pressure Fluctuation Characteristics of a Vertical Centrifugal Pump with Vaned Diffuser

2021 ◽  
Author(s):  
Yongshun Zeng ◽  
Zhifeng Yao ◽  
Ran Tao ◽  
Weichao Liu ◽  
Ruofu Xiao
Keyword(s):  
Centrifugal Pump ◽  
Pressure Fluctuation ◽  
Pressure Fluctuations ◽  
Hydraulic Performance ◽  
Wake Flow ◽  
Long Distance ◽  
Trailing Edge ◽  
Excessive Pressure ◽  
Vaned Diffuser ◽  
Rotor Stator Interaction

Abstract A vertical centrifugal pump with a vaned diffuser is very attractive in the field of long-distance water supply. Excessive pressure fluctuations in the vaneless region due to rotor stator interaction (RSI) need careful evaluation. In the present investigation, the hydraulic performance and pressure fluctuation characteristics of a vertical centrifugal pump with three different lean modes of the blade trailing edge were quantitatively analyzed by comparison experiments, using the same test rig. Results showed that the pressure fluctuation level was the highest in the vaneless region, closest to the volute tongue, and increased as the flowrate deviated from the design flowrate. The lean mode of the blade trailing edge was found to have a slight influence on hydraulic performance, and the relative deviation of experimental specific speeds with three different lean modes was within 6%. The influence of the lean mode of the blade trailing edge on the pressure fluctuation level was experimentally verified for the first time. In particular, the flowrate-averaged peak-to-peak value of pressure fluctuation with the positive lean mode (PLM) was 62% of the corresponding value with the zero lean mode (ZLM), while no significant improvement was observed for the negative lean mode (NLM). The flow mechanism behind this may be explained as a weakening of the jet-wake flow pattern with PLM.

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