scholarly journals Analysis of the Influence of Inlet Guide Vanes on the Performance of Shaft Tubular Pumps

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Haifeng Jiao ◽  
Chong Sun ◽  
Songshan Chen
Keyword(s):  
Flow Rate ◽  
Pressure Fluctuation ◽  
Pressure Pulsation ◽  
Hydraulic Loss ◽  
Flow Conditions ◽  
Significant Drop ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
Small Flow ◽  
Large Flow

To study the influence of inlet guide vanes (IGVs) on the pressure pulsation of a shaft tubular pump, this paper first conducts an experiment to study IGVs. Then, numerical calculations of the shaft tubular pump with and without IGVs are performed to analyze the hydraulic performance and pressure fluctuation characteristics. Finally, the reliability and accuracy of the data are verified by a model test. Numerical simulation results show that with additional IGVs, the pressure pulsation amplitude at the impeller inlet first decreases and then increases under small-flow and design conditions but gradually increases under large-flow conditions. When the IGVs are added to the impeller inlet of the shaft tubular pump, the hydraulic loss in front of the impeller inlet increases, resulting in a significant drop in the head and efficiency of the pump device when the flow rate is less than 1.12 Qd; when the flow rate is greater than 1.12Qd, the head and efficiency of the pump device do not change significantly. IGVs can improve the condition of impeller water inflow and reduce pressure fluctuation on the blade surface.

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.

scholarly journals Numerical and Experimental Analysis of Flow and Pulsation in Hump Section of Siphon Outlet Conduit of Axial Flow Pump Device

2021 ◽  
Vol 11 (11) ◽  
pp. 4941
Author(s):  
Fan Yang ◽  
Yiqi Zhang ◽  
Yao Yuan ◽  
Chao Liu ◽  
Zhongbin Li ◽  
...  
Keyword(s):  
Flow Field ◽  
Flow Rate ◽  
Vortex Structure ◽  
Pressure Fluctuation ◽  
Axial Flow ◽  
Mean Value ◽  
Hydraulic Loss ◽  
Pressure Amplitude ◽  
Measuring Point ◽  
Outlet Conduit

In order to study the variation law of the flow field and pressure fluctuation in the hump section of the siphon outlet conduit, the flow field characteristics and frequency spectrum characteristics of the flow field were analyzed by combining a physical model test and numerical simulation under the conditions of the interaction between the axial flow pump and siphon outlet conduit, and the influence of the residual circulation at the outlet of the guide vane on the siphon outlet flow was investigated. Based on the influence of the flow field and hydraulic loss in the conduit, the equivalent surface method based on the Q criterion was used to analyze the vortex structure in the siphon outlet conduit and to analyze the internal vortex state. The results showed that with the increase of the flow rate, the intensity of the vortices in the cross-section of the hump section of the siphon outlet conduit decreased gradually, the average velocity circulation decreased gradually and the axial velocity distribution uniformity increased and tended to be stable; water flow stratification existed under three characteristic conditions with no circulation, and the hydraulic loss was greater with the circulation flow while it had a circulation under the small flow condition. Under the low flow rate conditions, the hydraulic loss was 6.6 times higher under the condition of circulation than without. Under a high flow condition, it was 1.3 times. Under the condition of a small flow rate, the vortex structure was distributed centrally at the inlet of the flow conduit, and under the other two characteristic conditions, the vortex structure mostly appeared as a strip; the pressure fluctuation in the hump section had obvious periodicity, and with the increase of the flow rate, the maximum pressure fluctuation amplitude in the hump section decreased gradually; with the decrease of the rotational speed, the pressure amplitude at the same measuring point in the hump section decreased gradually and at the optimum condition. Under the following conditions, the mean value of the pressure amplitude at the top of the hump section was reduced by 69.63%, and the mean value of the pressure amplitude at the bottom of the hump section was reduced by 63.5%. Under all the calculation conditions, the main frequency of pulsation at each measuring point of the hump section was twice the frequency of the rotation.

Optimization of Inlet Ring Groove Arrangement for Suppression of Unstable Flow in a Centrifugal Impeller

2005 ◽  
Author(s):  
Masahiro Ishida ◽  
Daisaku Sakaguchi ◽  
Hironobu Ueki
Keyword(s):  
Flow Rate ◽  
The Other ◽  
Centrifugal Impeller ◽  
Shape Parameters ◽  
Unstable Flow ◽  
Ring Groove ◽  
Flow Rates ◽  
Small Flow ◽  
Specific Speed ◽  
Large Flow

An optimization of the inlet ring groove arrangement has been pursued in the present study for obtaining better impeller characteristics and a wider operation range at both small and large flow rates in a high specific speed type centrifugal impeller with inducer. The effects of the shape parameters with respect to the inlet ring groove on the impeller characteristic and the flow incidence were analyzed mainly based on numerical simulations, but also compared to the experimental results. At small flow rates, a significant improvement in the impeller characteristic is achieved due to reduction in the excessive-positive flow incidence by optimizing both location and width of the rear groove near the inducer tip throat. On the other hand, the impeller characteristic is improved at large flow rates by implementing the corner radius at the rear groove edge and by placing another front ring groove in the suction pipe. As a result, by the optimized configuration of the front and rear ring grooves, the unstable flow range of the test impeller can be reduced by about 50% without deterioration of the impeller characteristic even at the 125% flow rate.

scholarly journals Investigation of Speed Matching Affecting Contrarotating Fan’s Performance Using Wireless Sensor Network including Big Data and Numerical Simulation

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Hengxuan Luan ◽  
Liyuan Weng ◽  
Ranhui Liu ◽  
Yuanzhong Luan ◽  
Dongmin Li
Keyword(s):  
Big Data ◽  
Numerical Method ◽  
Flow Rate ◽  
Rate Condition ◽  
Small Flow Rate ◽  
Large Flow Rate ◽  
Small Flow ◽  
Power Capability ◽  
Two Stages ◽  
Large Flow

This paper describes the investigations performed to better understand two-stage rotor speed matching in a contrarotating fan. In addition, this study develops a comprehensive measuring and communication system for a contrarotating fan using ZigBee network. The investigation method is based on three-dimensional RANS simulations; the RANS equations are solved by the numerical method in conjunction with a SST turbulence model. A wireless measurement system using big data method is first designed, and then a comparison is done with experimental measurements to outline the capacity of the numerical method. The results show that when contrarotating fan worked under designed speed, performance of two-stages rotors could not be matched as the designed working condition was deviated. Rotor 1 had huge influences on flow rate characteristics of a contrarotating fan. Rotor 2 was influenced by flow rates significantly. Under large flow rate condition, the power capability of rotor 2 became very weak; under working small flow rate condition, overloading would take place to class II motor. In order to solve the performance mismatch between two stages of CRF under nondesigned working conditions, under small flow rate condition, the priority shall be given to increase of the speed of rotor 1, while the speed of rotor 2 shall be reduced appropriately; under large flow rate condition, the speed of rotor 1 shall be reduced and the speed of rotor 2 shall be increased at the same time.

scholarly journals Numerical and experimental investigation of the pressure fluctuation in a mixed-flow pump under low flow conditions

2019 ◽  
Vol 234 (1) ◽  
pp. 46-57 ◽  
Author(s):  
Xi Shen ◽  
Desheng Zhang ◽  
Bin Xu ◽  
Ruijie Zhao ◽  
Yongxin Jin ◽  
...  
Keyword(s):  
Flow Field ◽  
Flow Rate ◽  
Flow Separation ◽  
Pressure Fluctuation ◽  
Static Pressure ◽  
Leading Edge ◽  
Low Flow ◽  
Flow Conditions ◽  
Mixed Flow ◽  
Flow Pump

In this paper, the large eddy simulation is utilized to simulate the flow field in a mixed-flow pump based on the standard Smagorinsky subgrid scale model, which is combined with the experiments to investigate pressure fluctuations under low flow conditions. The experimental results indicated that the amplitude of fluctuation at the impeller inlet is the highest, and increases with the reduction of the flow rate. The main frequencies of pressure fluctuation at the impeller inlet, impeller outlet, and vane inlet are blades passing frequency, while the main frequency at the vane outlet changes with the flow rate. The results of the simulation showed that the axial plane velocity at impeller inlet undergoes little change under 0.8 Qopt. In case of 0.4 Qopt, however, the flow field at impeller inlet becomes complicated with the axial plane velocity changing significantly. The flow separation is generated at the leading edge of the suction surface at t* = 0.0416 under 0.4 Qopt, which is caused by the increase of the incidence angle and the influence of the tip leakage flow. When the impeller rotates from t* = 0.0416 to t* = 0.1249, the flow separation intensified and the swirling strength of the separation vortex is gradually increased, leading to the reduction of the static pressure, the rise of adverse pressure gradient, and the generation of backflow. The static pressure at the leading edge of the impeller recovers gradually until the backflow is reached. In addition, the flow separation is the main reason for the intensification of the pressure fluctuation.

Low-Solidity Tandem-Cascade Diffusers for Wide-Flow-Range Centrifugal Blowers

1983 ◽  
Author(s):  
Yasutoshi Senoo ◽  
Hiroshi Hayami ◽  
Hironobu Ueki
Keyword(s):  
Flow Rate ◽  
Pressure Recovery ◽  
Vaneless Diffuser ◽  
Simple Method ◽  
Small Flow Rate ◽  
Large Flow Rate ◽  
Wide Range ◽  
Small Flow ◽  
Series Of Experiments ◽  
Large Flow

The pressure recovery of a low-solidity circular cascade diffuser of a centrifugal blower was predicted by a simple method combining a theory of circular cascade diffusers and that of vaneless diffusers and it was compared with a series of experiments. Furthermore the stall limit of the diffuser was studied. In order to improve the performance further, a series of tandem-cascade diffusers were tested. In these diffusers, the front row of the cascade was designed for a small flow rate while the rear row of the cascade was designed for a large flow rate so that the tandem cascade would accomplish good pressure recovery in a wide range of flow rate. Experimental results showed that the operating range was as wide as that of a vaneless diffuser and the pressure recovery was excellent at a small flow rate while it was somewhat better than that in a vaneless diffuser at a large flow rate.

scholarly journals Analysis of Pressure Pulsation Induced by Rotor-Stator Interaction in Nuclear Reactor Coolant Pump

2017 ◽  
Vol 2017 ◽  
pp. 1-18 ◽  
Author(s):  
Xu Zhang ◽  
Pengfei Wang ◽  
Xiaodong Ruan ◽  
Zhongbin Xu ◽  
Xin Fu
Keyword(s):  
Flow Rate ◽  
Pressure Pulsation ◽  
Operating Conditions ◽  
Impeller Blade ◽  
Coolant Pump ◽  
Guide Vanes ◽  
Rate Distribution ◽  
Reactor Coolant ◽  
Rotor Stator Interaction ◽  
Phase Differences

The internal flow of reactor coolant pump (RCP) is much more complex than the flow of a general mixed-flow pump due to high temperature, high pressure, and large flow rate. The pressure pulsation that is induced by rotor-stator interaction (RSI) has significant effects on the performance of pump; therefore, it is necessary to figure out the distribution and propagation characteristics of pressure pulsation in the pump. The study uses CFD method to calculate the behavior of the flow. Results show that the amplitudes of pressure pulsation get the maximum between the rotor and stator, and the dissipation rate of pressure pulsation in impellers passage is larger than that in guide vanes passage. The behavior is associated with the frequency of pressure wave in different regions. The flow rate distribution is influenced by the operating conditions. The study finds that, at nominal flow, the flow rate distribution in guide vanes is relatively uniform and the pressure pulsation amplitude is the smallest. Besides, the vortex shedding or backflow from the impeller blade exit has the same frequency as pressure pulsation but there are phase differences, and it has been confirmed that the absolute value of phase differences reflects the vorticity intensity.

Analysis of Off-Design Flow Field and Prediction of Performance in Hydraulic Turbine

2014 ◽  
Vol 496-500 ◽  
pp. 877-880
Author(s):  
Feng Xia Shi ◽  
Jun Hu Yang ◽  
Xiao Hui Wang
Keyword(s):  
Flow Field ◽  
Pressure Distribution ◽  
Flow Rate ◽  
Pressure Fluctuation ◽  
Pressure Pulsation ◽  
Guide Vane ◽  
Hydraulic Turbine ◽  
Design Flow ◽  
External Characteristic ◽  
Distribution Of Flow

Two models of hydraulic turbine based on pump in reversal were simulated. Pressure distribution of flow field in Variable conditions was analysed and external characteristic was forecasted for hydraulic turbine. It was shown: the head increased with flow increased, with increasing of flow rate, efficiency first increased and then decreased. Compared with the turbine with a guide vane, the head of two models was almost equal, but the disparity of efficiency was large, and the efficiency of hydraulic turbine with a guide vane above on the efficiency of hydraulic turbine without guide vane. Pressure pulsation was existent in runner inlet. From runner inlet to runner outlet, the pressure distributed evenly from high to low. Added with a guide vane, the pressure distribution was more evenly than before and the Amplitude of pressure fluctuation decreased.

scholarly journals Effects of Inlet Guide Vanes on the Performance and Stability of an Aeronautical Centrifugal Compressor

2020 ◽  
Author(s):  
Nicolas Poujol ◽  
Isabelle Trébinjac ◽  
Pierre Duquesne
Keyword(s):  
Mass Flow ◽  
Flow Rate ◽  
Centrifugal Compressor ◽  
Compressor Stage ◽  
Lower Mass ◽  
Flow Angle ◽  
Guide Vanes ◽  
Inlet Guide Vanes ◽  
Surge Line ◽  
Stagger Angle

Abstract A research centrifugal compressor stage designed and built by Safran Helicopter Engines is tested at 3 IGV (Inlet Guide Vanes) stagger angles. The compressor stage includes 4 blade rows: axial inlet guide vanes, a backswept splittered impeller, a splittered vaned radial diffuser and axial outlet guide vanes. The methodology for calculating the performance is detailed, including the consideration of humidity in order to minimize errors related in particular to operating atmospheric conditions. The shift of the surge line towards lower mass flow rate as the IGV stagger angle increases highly depends on the rotation speed. The surge line shift is very small at low rotation speeds whereas it significantly increases at high rotation speeds. A firstorder stability analysis of the impeller and diffuser subcomponents shows that the diffuser (resp. impeller) is the first unstable component at low (resp. high) rotation speeds. This situation is unaltered by increasing the IGV stagger angle. At low rotation speeds below a given mass flow rate, rotating instabilities at the impeller inlet are detected at zero IGV stagger angle. Their occurrence is conditioned by the relative flow angle at the tip of the leading edge of the impeller. As the IGV stagger angle increases, the mass flow decreases to maintain a given inlet flow angle. Therefore, the onset of the rotating instabilities is delayed towards lower mass flow rates. At high rotation speeds, the absolute flow angle at the diffuser inlet near surge decreases as the IGV stagger angle increases. As a result, the flow is highly alternate over two adjacent channels of the radial diffuser beyond the surge line at IGV stagger angle of 0°.

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