Study on the characteristics of horn-like vortices in an axial flow pump impeller under off-design conditions

Zhao, Hao-ru; Wang, Fujun; Wang, Chaoyue; Chen, Wenhao; Yao, Zhifeng; Shi, Xiaoyan; Li, Xiaoqin; Zhong, Qiang

doi:10.1080/19942060.2021.1985615

Cited by 37 publications

(9 citation statements)

References 26 publications

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“…The consequences of Wang et al 33 study can be seen in Figure 4, which illustrates the importance of PR. The HT augmentation achieved is proportional to the downwash capability of the vortex flow over the tube bundle.…”

Section: Resultsmentioning

confidence: 90%

The influence of geometrical and operational parameters on thermofluid performance of discontinuous colonial self‐swirl‐inducing baffle plate in a tubular heat exchanger

Rahman

2023

Heat Trans

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An exploratory investigation was conducted to analyze a tubular heat exchanger's turbulent heat transfer characteristics using an innovative baffle plate design. The design incorporated a perforated conical baffle plate and an adjustable rectangular deflector. The strategic placement of this baffle plate at the heat exchanger inlet facilitated a swirling flow downstream. To assess the impact of this design, three baffle plates with varying pitch ratios (l/D) were positioned in the direction of the flow. The study examined the effects of pitch ratio (ranging from 0.6 to 1.2), deflector inclination angle (ranging from 30° to 50°), and Reynolds numbers (ranging from 16,500 to 29,500). Moreover, the size of the conical baffle plate (H/D) was altered (from 0.25 to 0.15). The findings highlighted the substantial influence of pitch ratio, inclination angle, and height ratio on the heat exchanger's performance. Notably, the configuration featuring an inclination angle of 50° and height ratio of 0.15 exhibited an average performance improvement of 22% compared to other height ratios, inclination angles, and pitch ratios.

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Section: Resultsmentioning

confidence: 90%

The influence of geometrical and operational parameters on thermofluid performance of discontinuous colonial self‐swirl‐inducing baffle plate in a tubular heat exchanger

Rahman

2023

Heat Trans

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“…Nevertheless, an undue surge in turbulence can escalate pressure depletion energy expenditure, culminating in unfavourable outcomes like erosion and excessive acoustics. The findings of Zhao et al 45 are reflected in Figure 5, demonstrating the significance of PR. The HT improvement directly F I G U R E 5 Relative Nu/Nu 0 with PR.…”

Section: Ht Intensificationmentioning

confidence: 75%

“…The deviations from the experimental data were +8.195 for Dittus and Boelter, −0.649 for Colebrook‐White, −9.054 for Gnielinski, and +0.73 for Blasius on average. The uncertainty associated with the measuring instrument was calculated using Coleman and Steele, 45 with its value for the thermocouple is ±0.5°C, pressure is ±0.1 Pa, flow meter is ±0.006 m/s.…”

Section: Methodsmentioning

confidence: 99%

The effect of triangular shutter type flow deflector perforated baffle plate on the thermofluid performance of a heat exchanger

Rahman

2023

Heat Trans

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The study aimed to investigate the heat transfer (HT) properties of a tubular heat exchanger (HX) by using innovative baffle plate arrangements. The newly designed baffle plate was circular with triangular openings and adjustable triangular flow deflectors. These deflectors were strategically placed at the inlet of the HX to create a swirling flow downstream. Three baffle plates were installed along the flow direction with different length‐to‐diameter ratios (pitch ratios) to assess their impact on HT, pressure drop, and thermal enhancement factor. The study compared these results with a smooth channel under varying Reynolds numbers (16,500–29,500). The findings revealed that both the pitch ratio (0.6–1.2) and the inclination angle of the deflectors (30⁰–50⁰) significantly affected the HX's performance. Notably, the baffle plate with a deflector inclination angle of 30° and a pitch ratio of 1 showed a remarkable average improvement of 36.5% compared to other angles and ratios.

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“…The grid reliability verification index uses GCI (Grid Convergence Index) as the evaluation standard [ 33 , 34 ]. Three groups of grids are selected from seven various grid numbers for grid convergence analysis.…”

Section: Mathematical Model and Numerical Simulation Methodsmentioning

confidence: 99%

Analysis of Energy Loss Characteristics of Vertical Axial Flow Pump Based on Entropy Production Method under Partial Conditions

Yang

Chang

Cai³

et al. 2022

Entropy

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The energy loss of the vertical axial flow pump device increases due to the unstable internal flow, which reduces the efficiency of the pump device and increases its energy consumption of the pump device. The research results of the flow loss characteristics of the total internal conduit are still unclear. Therefore, to show the internal energy loss mechanism of the axial flow pump, this paper used the entropy production method to calculate the energy loss of the total conduit of the pump device to clarify the internal energy loss mechanism of the pump device. The results show that the energy loss of the impeller is the largest under various flow conditions, accounting for more than 40% of the total energy loss of the pump device. The variation trend of the volume average entropy production and the energy loss is similar under various flow coefficients (KQ). The volume average entropy production rate (EPR) and the energy loss decrease first and then increase with the increase of flow, the minimum volume average entropy production is 378,000 W/m3 at KQ = 0.52, and the area average EPR of the impeller increases gradually with the increase of flow. Under various flow coefficient KQ, the energy loss of campaniform inlet conduit is the smallest, accounting for less than 1% of the total energy loss. Its maximum value is 63.58 W. The energy loss of the guide vane and elbow increases with the increase of flow coefficient KQ, and the maximum ratio of energy loss to the total energy loss of the pump device is 29% and 21%, respectively, at small flow condition KQ = 0.38. The energy loss of straight outlet conduit reduces first and then increases with the increase of flow coefficient KQ. When flow coefficient KQ = 0.62, it accounts for 27% of the total energy loss of the pump device, but its area average entropy production rate (EPR) and volume average entropy production rate (EPR) are small. The main entropy production loss in the pump device is dominated by entropy production by turbulent dissipation (EPTD), and the proportion of entropy production by direct dissipation (EPDD) is the smallest.

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Study on the characteristics of horn-like vortices in an axial flow pump impeller under off-design conditions

Cited by 37 publications

References 26 publications

The influence of geometrical and operational parameters on thermofluid performance of discontinuous colonial self‐swirl‐inducing baffle plate in a tubular heat exchanger

The influence of geometrical and operational parameters on thermofluid performance of discontinuous colonial self‐swirl‐inducing baffle plate in a tubular heat exchanger

The effect of triangular shutter type flow deflector perforated baffle plate on the thermofluid performance of a heat exchanger

Analysis of Energy Loss Characteristics of Vertical Axial Flow Pump Based on Entropy Production Method under Partial Conditions

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