Fengxia Shi^1,2, Guangbiao Zhao^1,*, Yucai Tang¹, Dedong Ma¹, Xiangyun Shi¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.11, pp. 2617-2636, 2024, DOI:10.32604/fdmp.2024.053186 - 28 October 2024

Abstract To analyze the effect of blade number on the performance of hydraulic turbines during the transient stage in which the flow rate is not constant, six hydraulic turbines with different blade numbers are considered. The instantaneous hydraulic performance of the turbine and the pressure pulsation acting on the impeller are investigated numerically by using the ANSYS CFX software. The ensuing results are compared with the outcomes of experimental tests. It is shown that the fluctuation range of the pressure coefficient increases with time, but the corresponding range for the transient hydraulic efficiency decreases gradually when… More >

Tiantian Yu¹, Youping Lv¹, Hao Zhong², Ming Liu¹, Pingyuan Gai¹, Zeju Jiang¹, Peng Zhang¹, Xingkai Zhang^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.8, pp. 1759-1772, 2024, DOI:10.32604/fdmp.2024.049035 - 06 August 2024

Abstract A new measurement device, consisting of swirling blades and capsule-shaped throttling elements, is proposed in this study to eliminate typical measurement errors caused by complex flow patterns in gas-liquid flow. The swirling blades are used to transform the complex flow pattern into a forced annular flow. Drawing on the research of existing blockage flow meters and also exploiting the single-phase flow measurement theory, a formula is introduced to measure the phase-separated flow of gas and liquid. The formula requires the pressure ratio, Lockhart-Martinelli number (L-M number), and the gas phase Froude number. The unknown parameters More >

Fengxia Shi^1,2, Guangbiao Zhao^1,*, Yucai Tang¹, Haonan Zhan¹, Pengcheng Wang¹

Sound & Vibration, Vol.58, pp. 101-117, 2024, DOI:10.32604/sv.2024.047082 - 11 March 2024

Abstract In order to study the effect of splitter blades on the internal and external sound field of the hydraulic turbine, the paper chose a centrifugal pump with a specific speed n_s = 33 reversed as a hydraulic turbine as the research object, and added the short blades on the original impeller to form a new splitter impeller. Based on the Re-Normalization Group (RNG) k-ε turbulence model to conduct numerical simulation for the hydraulic turbine, this thesis calculated the internal and external acoustic field by means of the acoustic boundary element (BEM) and finite element (FEM) and… More >

Xiaorui Cheng^1,2,*, Yimeng Jiang¹, Min Li¹, Shuyan Zhang¹

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.5, pp. 1047-1061, 2020, DOI:10.32604/fdmp.2020.010695 - 09 October 2020

Abstract The influence of the axial mount position of the guide vane on the pressure fluctuation in a nuclear pump (AP1000) is investigated. The characteristics of the three-dimensional flow inside the nuclear pump are analyzed by means of numerical simulation. Results indicate that when the axial relative distance between the guide vane and the pumping chamber is reduced, in conditions of “small flow,” the efficiency of the pump increases, the pressure inside the pumping chamber decreases, while the losses related to the guide vane grow. Under large flow conditions, as the efficiency of the pump decreases, More >

Jiacheng Dai¹, Jiegang Mou^{1, *}, Tao Liu¹

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.2, pp. 161-179, 2020, DOI:10.32604/fdmp.2020.06613 - 21 April 2020

Abstract The automobile engine pump is an important part of the automobile cooling system, and has a direct influence on the engine performance. Based on the SST k-ω turbulence model, unsteady numerical simulation for an automobile engine pump with different tip clearances was carried out by Fluent. To study the flow field characteristics and pressure fluctuation, the characteristics of secondary flow distribution in volute are also analyzed. The result shows that the pressure fluctuation characteristics of the flow field show obvious periodic variation at different levels of tip clearances. The peak value of pressure fluctuation at… More >

Hayder A. Abdulbari ^1,2, Hassan D. Mahammed¹, Z. Hassan, Wafaa K. Mahmood³

FDMP-Fluid Dynamics & Materials Processing, Vol.12, No.2, pp. 86-101, 2016, DOI:10.3970/fdmp.2016.012.086

Abstract An experimental investigation was carried out to study the response of a turbulent pressure drop fluctuations to longitudinal groove riblets, involved two configurations being triangular and spaced triangular grooves with height 600, 800, 1000 μm and peak to peak spacing 1000 μm and 2000 μm respectively. Experiments were therefore performed at free stream velocity up to 0.44 m/sec, which were corresponding to Reynolds number (Re) 53000. The development of the obtained turbulent layer downstream of the grooves was then compared with the results from the corresponding smooth-wall case. To conclude, the effect of the spaced More >