Numerical Flow Simulation and Cavitation Prediction in a Centrifugal Pump
                        using an SST-SAS Turbulence Model

Ennouri, Marwa; Kanfoudi, Hatem; Taher, Ahmed; Zgolli, Ridha

doi:10.29252/jafm.75.253.28771

Cited by 11 publications

(4 citation statements)

References 48 publications

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“…The results revealed that the calculated cavitation performance curve agreed well with the experimental measurements and the pressure fluctuation induced by cavitation was stronger than that of non-cavitation condition. Ennouri et al [12] investigated the centrifugal pump by scale-adapted simulation (SAS) through non-cavitation and cavitation conditions and the results showed an acceptable agreement with testing data. On the other hand, an effective cavitation model is another fundamental technique for CFD research of cavitation, which can describe the interphase mass transfer between the liquid and vapor phases.…”

Section: Introductionmentioning

confidence: 98%

Influence of Cavitation on Unsteady Vortical Flows in a Side Channel Pump

Wang

Zhang

Yuan

et al. 2023

Chin. J. Mech. Eng.

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Previous investigation on side channel pump mainly concentrates on parameter optimization and internal unsteady vortical flows. However, cavitation is prone to occur in a side channel pump, which is a challenging issue in promoting performance. In the present study, the cavitating flow is investigated numerically by the turbulence model of SAS combined with the Zwart cavitation model. The vapors inside the side channel pump firstly occur in the impeller passage near the inlet and then spread gradually to the downstream passages with the decrease of NPSHa. Moreover, a strong adverse pressure gradient is presented at the end of the cavity closure region, which leads to cavity shedding from the wall. The small scaled vortices in each passage reduce significantly and gather into larger vortices due to the cavitation. Comparing the three terms of vorticity transport equation with the vapor volume fraction and vorticity distributions, it is found that the stretching term is dominant and responsible for the vorticity production and evolution in cavitating flows. In addition, the magnitudes of the stretching term decrease once the cavitation occurs, while the values of dilatation are high in the cavity region and increase with the decreasing NPSHa. Even though the magnitude of the baroclinic torque term is smaller than vortex stretching and dilatation terms, it is important for the vorticity production along the cavity surface and near the cavity closure region. The pressure fluctuations in the impeller and side channel tend to be stronger due to the cavitation. The primary frequency of monitor points in the impeller is 24.94 Hz and in the side channel is 598.05 Hz. They are quite corresponding to the shaft frequency of 25 Hz (fshaft = 1/n = 25 Hz) and the blade frequency of 600 Hz (fblade = Z/n =600 Hz) respectively. This study complements the investigation on cavitation in the side channel pump, which could provide the theoretical foundation for further optimization of performance.

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Section: Introductionmentioning

confidence: 98%

Influence of Cavitation on Unsteady Vortical Flows in a Side Channel Pump

Wang

Zhang

Yuan

et al. 2023

Chin. J. Mech. Eng.

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“…When the local pressure is less than the saturated vapor pressure, cavitation (a type of complex multiphase flow) may occur in the centrifugal pump (Ennouri et al 2019). Under most operating conditions, cavitation induces harmful effects and can have detrimental consequences.…”

Section: Introductionmentioning

confidence: 99%

Effects of the Centrifugal Pump Outlet Blade Angle on Its Internal Flow Field Characteristics under Cavitation Condition

Wang

Zhao²,

Han³

et al. 2023

JAFM

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The outlet blade angle is a key geometrical parameter that governs how the impeller directly influences centrifugal pump performance. Therefore, a reasonable angle selection is crucial. To investigate the effects of the outlet blade angle on centrifugal pump internal flow field characteristics under cavitation conditions, this study employs a combination of a modified SST k-ω turbulent model with a Zwart-Gerber-Belamri cavitation model to perform transient flow simulations. Outlet blade angles of 15°, 20°, 25°, 30°, and 35° were tested. The results indicated that as the outlet blade angle increased, the relative liquid flow angle, vapor volume, and corresponding fraction first increased, then decreased, and finally increased again. Meanwhile, the distribution scope of each stall vortex on the suction surface became smaller, then larger, and smaller again, whereas the scopes of the pressure surfaces grew constantly as the outlet blade angle increased. Pressure fluctuations at all monitored points in the volute became weaker over time, and variations in the pressure fluctuations alternated with the outlet blade angle. The main frequency amplitude increased and the frequency doubling decreased as the outlet blade angle increased. Although the energy corresponding to the main frequency was unstable, it consistently held the dominant position. The duration that cavitation compliance was less than 0 first decreased and then increased as the outlet blade angle increased. For the impeller with an outlet blade angle of 25°, stall vortices accounted for the smallest regions, and the duration of negative cavitation compliance was minimized. In this case, the overall performance of the centrifugal pump was optimal.

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“…Regarding Shinde et al [30], they performed a large eddy simulation of a flow over a wall-mounted cube-shaped obstacle placed in a spatially evolving boundary layer for the purpose of understanding how variations in the cube height can modify the flow dynamics in the case where the cube is inside the boundary layer. Likewise, Ennouri et al [31] carried out the modelling and simulation of the flow inside a centrifugal pump, under cavitation and noncavitation conditions, using the SST-SAS turbulence model. Similarly, Zakaria et al [32] implemented an experimental study on a flat plate air solar collector.…”

Section: Introductionmentioning

confidence: 99%

Turbulent Flow Around Obstacles: Simulation and Study with Variable Roughness

Yousfi¹,

Aliane²

2021

IJHT

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The present work aims to investigate the recirculation and incipient mixing zones in a channel flow supplied with obstacles. The main objective is to develop a new technique to control these recirculation zones by setting a variable roughness. For the purpose of varying that roughness, 4 small bars of heights 0.25H, 0.5H, 0.75H and H were placed downstream of the obstacle; H is the height of the obstacle. For this, a three-dimensional numerical approach was carried out using the ANSYS CFX computer code. In addition, the governing equations were solved using the finite volume method. The K-ω shear-stress transport (SST) turbulence model was utilized to model the turbulent stresses. In the end, we presented the time-averaged simulation results of the contours of the current lines (3D time-averaged streamlines, trace-lines), three components of the velocities: <u> (velocity u contour), <v> (velocity v contour) and <w> (velocity w contour), trace-lines, stream ribbons and mean Q-criterion iso-surface.

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Numerical Flow Simulation and Cavitation Prediction in a Centrifugal Pump using an SST-SAS Turbulence Model

Cited by 11 publications

References 48 publications

Influence of Cavitation on Unsteady Vortical Flows in a Side Channel Pump

Influence of Cavitation on Unsteady Vortical Flows in a Side Channel Pump

Effects of the Centrifugal Pump Outlet Blade Angle on Its Internal Flow Field Characteristics under Cavitation Condition

Turbulent Flow Around Obstacles: Simulation and Study with Variable Roughness

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