Cavitation-Induced Unsteady Flow Characteristics in the First Stage of a Centrifugal Charging Pump

Zhang, Jinfeng; Yuan, Shouqi; Fu, Qiang; Pei, Ji; Böhle, Martin; Xusong, Jiang

doi:10.1115/1.4034362

Cited by 21 publications

(14 citation statements)

References 22 publications

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“…In the present study, first, the net positive suction head required (NPSH re ), which is an important parameter for evaluating the suction performance of the pump (Limbach & Skoda, 2017;Zhang et al, 2017), is selected as the objective function. In addition, the suction performance can be expressed by the suction specific speed (N ss ) using the objective function.…”

Section: Objective Functionmentioning

confidence: 99%

“…The results of this study can be used as an effective reference to help understand and control the complex phenomena occurring in cavitating flows in centrifugal pumps operating under low flow rates. Zhang et al (2017) investigated the unsteady cavitation characteristics of a centrifugal charging pump. The vapor generation and the growth and collapse of vapor bubbles during the cavitation influenced the pressure and velocity fluctuations.…”

Section: Introductionmentioning

confidence: 99%

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Multi-objective optimization of a high efficiency and suction performance for mixed-flow pump impeller

Suh

Yang

Kim

et al. 2019

Engineering Applications of Computational Fluid Mechanics

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This research aimed to systematically maximize hydraulic efficiency and suction specific speed for mixed-flow pump using a commercial CFD packages and optimization tool. First, mixed-flow pump was initially designed according to the traditional design method, and then the blade shape was redesigned by focusing on the hydraulic efficiency. Second, the efficiency-oriented optimum design was selected as the reference model. The objective was to improve the suction specific speed under the specific condition of the mixed-flow pump through the multi-objective optimization technique. The incidence angles and meridional plane were optimized through a systematic optimization process, namely, central composite method and response surface approximation. The optimization results indicated that the suction specific speed values of the reference and optimum model were 88.13 and 289.65, respectively. Furthermore, the hydraulic efficiency was kept within ± 1% compared to the reference model as the constraint condition. The hydraulic efficiency of the reference and optimum model were 91.44% and 90.40%, respectively. The reasons for the improved efficiency and suction performance were investigated through internal flow field analysis. Finally, the reliability of the optimization was demonstrated by comparing the numerical and experimental results. ARTICLE HISTORY

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Section: Objective Functionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Multi-objective optimization of a high efficiency and suction performance for mixed-flow pump impeller

Suh

Yang

Kim

et al. 2019

Engineering Applications of Computational Fluid Mechanics

View full text Add to dashboard Cite

show abstract

“…Zhang et al explained NSPHa (available NPSH) as the suction head available at the pump impeller inlet, whereas NPSHr (required) is the least suction head the pump needs so as to avoid excessive cavitation and pump performance degradation. This is usually referred to as NPSH3, since at a cavitation-induced head impairment ≥3% the cavitating pump will undergo significant cavitation, which eventually leads to head breakdown [9,15].…”

Section: Introductionmentioning

confidence: 99%

“…Although this boundary set has been fruitfully implemented in numerical simulations with and without cavitation models [16][17][18][19][20], the choice of total inlet pressure is by guessing if there is no foreknowledge of the NPSHr range [21][22][23][24]. This approach usually requires about 10-15 independent simulations before a good accuracy is reached [15,16]. Moreover, this pure guessing game is likely to draw the simulation into severe cavitation conditions, which take far longer times to converge, especially in situations where transient simulations are required to acquire the necessary accuracy [14,25].…”

Section: Introductionmentioning

confidence: 99%

A Practical Method for Speeding up the Cavitation Prediction in an Industrial Double-Suction Centrifugal Pump

et al. 2019

Self Cite

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Researches have over the past few years have been applying optimization algorithms to quickly find optimum parameter combinations during cavitation optimization design. This method, although better than the traditional trial-and-error design method, consumes lots of computational resources, since it involves several numerical simulations to determine the critical cavitation point for each test case. As such, the Traditional method for NPSHr prediction was compared to a novel and alternative approach in an axially-split double-suction centrifugal pump. The independent and dependent variables are interchanged at the inlet and outlet boundary conditions, and an algorithm adapted to estimate the static pressure at the pump outlet. Experiments were conducted on an original size pump, and the two numerical procedures agreed very well with the hydraulic and cavitation results. For every flow condition, the time used by the computational resource to calculate the NPSHr for each method was recorded and compared. The total number of hours used by the new and alternative approach to estimate the NPSHr was reduced by 54.55% at 0.6 Qd, 45.45% at 0.8 Qd, 50% at 1.0 Qd, and 44.44% at 1.2 Qd respectively. This new method was demonstrated to be very efficient and robust for real engineering applications and can, therefore, be applied to reduce the computation time during the application of intelligent cavitation optimization methods in pump design.

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“…The centrifugal pump, as one of the most widely used hydraulic machinery, is designed to be much speedier and much larger to meet the industrial demands. However, the benefit always accompanies with disadvantage-the cavitation occurs when the fluid flows through the pump inlet to the impeller [1][2][3][4]. On the ground that the axial flow direction abruptly turns into radial with decreasing passageway, and thus reduces the local pressure.…”

Section: Introductionmentioning

confidence: 99%

Rotating Corrected-Based Cavitation Model for a Centrifugal Pump

Wang

Liu

et al. 2018

Journal of Fluids Engineering

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Cavitation has bothered the hydraulic machinery for centuries, especially in pumps. It is essential to establish a solid way to predict the unsteady cavitation evolution with considerable accuracy. A novel cavitation model was proposed, considering the rotating motion characteristic of centrifugal pump. Comparisons were made with three other cavitation models and validated by experiments. Considerable agreements can be noticed between simulations and tests. All cavitation models employed have similar performance on predicting the pump head drop curve with proper empirical coefficients, and also the unsteady cavitation evolution was well solved. The proposed rotating corrected-based cavitation model (rotating based Zwart-Gerber-Belamri (RZGB)) obtained identical triangle cavity structure with the experiment visualizations, while the others also got triangle structure but with opposite direction. The maximum flow velocity in the impeller passage appears near the shroud, contributing to the typical triangle cavity structure. A preprocessed method for instant rotating images was carried out for evaluating the erosion risk area in centrifugal pump, based on the standard deviation of gray level. The results imply that the unsteady rear part of the attached cavity is vulnerable to be damaged, where the re-entrant flow was noticed. This work presented a suitable cavitation model and reliable numerical simulation approach for predicting cavitating flows in centrifugal pump.

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Cavitation-Induced Unsteady Flow Characteristics in the First Stage of a Centrifugal Charging Pump

Cited by 21 publications

References 22 publications

Multi-objective optimization of a high efficiency and suction performance for mixed-flow pump impeller

Multi-objective optimization of a high efficiency and suction performance for mixed-flow pump impeller

A Practical Method for Speeding up the Cavitation Prediction in an Industrial Double-Suction Centrifugal Pump

Rotating Corrected-Based Cavitation Model for a Centrifugal Pump

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