Numerical simulation of transient mixed convection of water–Cu nanofluid in a square cavity with multiple rotating cylinders having harmonic motion

Shirani, Nima; Toghraie, Davood; Zarringhalam, Majid; Afrand, Masoud

doi:10.1007/s10973-020-09379-3

Cited by 14 publications

(5 citation statements)

References 32 publications

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“…This article conducted rapid starting and stopping external characteristic experiments on an atypical open impeller low specific speed centrifugal pump, and obtained the transient external characteristic changes during the starting and stopping processes, but did not conduct numerical simulation calculations. Further and more detailed internal characteristics research [26][27][28] will be conducted on atypical open impeller low specific speed centrifugal pumps using numerical simulation in the next work.…”

Section: Discussionmentioning

confidence: 99%

Transient Hydraulic Performance of a Prototype Pump during Starting and Stopping Periods

Zheng,

Ye,

Zhao

et al. 2023

Processes

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In order to meet different operational requirements, existing low specific speed centrifugal pumps may have to be run at high speeds. Therefore, it is crucial to understand the transient performance of such centrifugal pumps during high speed starting and stopping. However, there are currently no experiments on the starting and stopping of low specific speed centrifugal pumps. In this paper, transient hydraulic performance experiments during starting and stopping had been carried out on an atypical open impeller centrifugal pump with a rated flow rate of 6 m3/h using an updated test rig. The correlation of speed, flow, head and shaft power with time was obtained for four flow ratios of 0.353, 1.022, 1.654 and 2.343 operating conditions. It was found that the fluctuation of the shaft power curve was the strongest during the starting process, and there was a significant impact phenomenon. The corresponding impact shaft power from small to large flow rates were 0.167 kW, 0.409 kW, 0.234 kW and 0.215 kW, and the shaft power impact phenomenon was the most obvious under rated operating conditions. During the stopping process, the speed, flow rate and head all remain stable for a small period of time, and the time required to decrease to 0 is longer than the time required to reach a stable state during starting. During stopping, the shaft power will instantly decrease, accompanied by varying degrees of fluctuations.

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Section: Discussionmentioning

confidence: 99%

Transient Hydraulic Performance of a Prototype Pump during Starting and Stopping Periods

Zheng,

Ye,

Zhao

et al. 2023

Processes

View full text Add to dashboard Cite

show abstract

“…It was noted that the highest HT contribution was achieved by using the optimized porous media. There are a few works that considered the installation of more than two rotating CCs in confined spaces [6] , [7] .…”

Section: Introductionmentioning

confidence: 99%

Magneto-convection of nanofluid flow over multiple rotating cylinders in a confined space with elastic walls and ventilated ports

Selimefendigil,

Ghachem,

Albalawi

et al. 2024

Heliyon

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“…The size, location and conductivity of the cylinders were found to be important key parameters of the HT enhancement along with the rotational speed (Rs) as it has been shown in many C-HT studies within cavities or channels [10][11][12][13][14]. Even though in many studies related to C-HT in channel/cavity single RCs have been considered, there are a few cases where multiple rotating cylinder effects are encountered [15][16][17].…”

Section: Introductionmentioning

confidence: 99%

Forced Convection of Non-Newtonian Nanofluid Flow over a Backward Facing Step with Simultaneous Effects of Using Double Rotating Cylinders and Inclined Magnetic Field

et al. 2021

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The forced convection of non-Newtonian nanofluid for a backward-facing flow system was analyzed under the combined use of magnetic field and double rotating cylinders by using finite element method. The power law nanofluid type was used with different solid volume fractions of alumina at 20 nm in diameter. The effects of the Re number (100≤Re≤300), rotational Re number (−2500≤Rew≤3000), Ha number (0≤Ha≤50), and magnetic field inclination (0≤γ≤90) on the convective heat transfer and flow features were numerically assessed. The non-Newtonian fluid power law index was taken between 0.8 and 1.2 while particle volume fractions up to 4% were considered. The presence of the rotating double cylinders made the flow field complicated where multiple recirculation regions were established near the step region. The impacts of the first (closer to the step) and second cylinders on the heat transfer behavior were different depending upon the direction of rotation. As the first cylinder rotated in the clockwise direction, the enhancement in the average heat transfer of 20% was achieved while it deteriorated by approximately 2% for counter-clockwise directional rotation. However, for the second cylinder, both the rotational direction resulted in heat transfer augmentation while the amounts were 14% and 18% at the highest speeds. Large vortices on the upper and lower channel walls behind the step were suppressed with magnetic field effects. The average Nu number generally increased with the higher strengths of the magnetic field and inclination. Up to 30% increment with strength was obtained while this amount was 44% with vertical orientation. Significant impacts of power law fluid index on the local and average Nu number were seen for an index of n = 1.2 as compared to the fluid with n = 0.8 and n = 1 while an average Nu number of 2.75 times was obtained for the flow system for fluid with n = 1.2 as compared to case for fluid with the n value of 0.8. Further improvements in the local and average heat transfer were achieved with using nanoparticles while at the highest particle amount, the enhancements of the average Nu number were 34%, 36% and 36.6% for the fluid with n values of 0.8, 1 and 1.2, respectively.

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Numerical simulation of transient mixed convection of water–Cu nanofluid in a square cavity with multiple rotating cylinders having harmonic motion

Cited by 14 publications

References 32 publications

Transient Hydraulic Performance of a Prototype Pump during Starting and Stopping Periods

Transient Hydraulic Performance of a Prototype Pump during Starting and Stopping Periods

Magneto-convection of nanofluid flow over multiple rotating cylinders in a confined space with elastic walls and ventilated ports

Forced Convection of Non-Newtonian Nanofluid Flow over a Backward Facing Step with Simultaneous Effects of Using Double Rotating Cylinders and Inclined Magnetic Field

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