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 >

Hayder Kareem Sakran^1,2, Mohd Sharizal Abdul Aziz^1,*, Chu Yee Khor³

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.1, pp. 109-137, 2024, DOI:10.32604/cmes.2024.047245 - 16 April 2024

Abstract The centrifugal pump is a prevalent power equipment widely used in different engineering patterns, and the impeller blade wrap angle significantly impacts its performance. A numerical investigation was conducted to analyze the influence of the blade wrap angle on flow characteristics and energy distribution of a centrifugal pump evaluated as a low specific speed with a value of 69. This study investigates six impeller models that possess varying blade wrap angles (95°, 105°, 115°, 125°, 135°, and 145°) that were created while maintaining the same volute and other geometrical characteristics. The investigation of energy loss… More > Graphic Abstract

Tianyu Xu, Zhouming Su, Yanru Su, Zonglei Li, Quanjie Chen, Shuteng Zhi, Ennan Zheng^*, Kaili Meng

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.8, pp. 2147-2160, 2023, DOI:10.32604/fdmp.2023.025556 - 04 April 2023

Abstract The leaf-vein drip irrigation emitter is a new type of drip emitter based on a bionic structure able to support shunting, sharp turns, and increased dissipation. In the present work, the results of twenty-five tests executed in the framework of an orthogonal design strategy are presented in order to clarify the influence of the geometrical parameters of the flow channel on the hydraulic characteristics of such emitter. The corresponding flow index and head loss coefficient are determined through numerical simulations and model testing. The results show that the flow index of the flow channel is… More >

M. O. Petinrin^a , B. A. Sikirullahi^a, T. T. Olugasa^a, O. M. Oyewola^a,b,*

Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-8, 2022, DOI:10.5098/hmt.19.28

Abstract Tubes are commonly employed in heat exchangers for their ease of production and capacity to sustain high pressure. In this study, the heat and flow transfer behaviour of cam-shaped tube bank in staggered configuration at varying angles of attack 0°to 180° was numerically investigated. The study was carried out by solving the continuity, momentum, energy and realizable k-ε transport equations using the finite volume-based ANSYS Fluent solver. This was performed to acquire the friction factor and heat transfer characteristics in the air inlet velocity range of 9 to 15 m/s. The results showed that the… More >

Yulin Tian^a , Chengyi Long^b, Linghong Tang^a,*

Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-11, 2022, DOI:10.5098/hmt.19.18

Abstract In this study, the thermal-hydraulic performance of eight different printed circuit heat exchanger (PCHE) configurations with supercritical liquefied natural gas as the working fluid are studied by a numerical method. Firstly, the thermal-hydraulic performance of the PCHE with different airfoil fins are investigated at different operating pressures, which indicate that the PCHE with airfoil fins has better thermal performance but worse hydraulic performance when it operates at higher pressure condition. Furthermore, the effects of different airfoil configurations on the thermal-hydraulic performance are analyzed in detail. The results show that asymmetric airfoils can provide better heat More >

Nitesh Kumar, Shiva Kumar^*

Frontiers in Heat and Mass Transfer, Vol.19, pp. 10-11, 2022, DOI:10.5098/hmt.19.10

Abstract In the present study, the use of wavy fin turbulators on the annulus body of a double pipe air heater has been numerically investigated. The inner pipe consists of hot water whereas the annular section consists of cold air whose Reynolds Number (Re) ranged from 3000-15,000. Rectangular crosssectioned wavy fin turbulators with various curvature ratios of 2, 3, 5, and 7.5 is numerically simulated to investigate the influence of curvature effects on turbulence. Results have been compared with the bare pipe and with rectangular straight fins. It is seen that wavy fin turbulators perform better More >

Sushil Kumar^a , Robin Thakur^a, Amar Raj Singh Suri^a, Kamal Kashyap^a, Arvind Singhy^a, Sunil Kumar^a, Anil Kumar^b

Frontiers in Heat and Mass Transfer, Vol.16, pp. 1-11, 2021, DOI:10.5098/hmt.16.4

Abstract Solar thermal collector is a simple, economic, and environment friendly equipment which is used to utilize solar energy for various agriculture and industrial applications. The investigators mainly focus on the improvement of the thermal performance by providing various fins shapes underside of the absorber plate in the single pass and double pass solar thermal collector. This work discusses the influence of different shaped fins used by various researchers in improving the thermal performance of thermal collectors. Fin’s design, geometries used, and their influence on turbulence and thermal performance have also been discussed. As per the More >

Weiwei Zhang, Linghong Tang^*

Frontiers in Heat and Mass Transfer, Vol.15, pp. 1-7, 2020, DOI:10.5098/hmt.15.9

Abstract Air-side thermal and hydraulic performance of the finned flat-tube heat exchanger with single row is experimentally investigated. The correlations of the thermal and hydraulic performance are developed based on the experimental data. The effects of various fin geometrical parameters on the thermal and hydraulic performance are investigated by a numerical method, and the influence of various parameters is analyzed in detail. Results show that heat transfer performance and pressure drop decrease with the increasing fin pitch, and heat transfer performance increases with the increase of fin length and fin height accompanying with the increase of More >

Withada Jedsadaratanachai^a, Amnart Boonloi^b,*

Frontiers in Heat and Mass Transfer, Vol.6, pp. 1-19, 2015, DOI:10.5098/hmt.6.13

Abstract Numerical investigations on flow topology, heat transfer behavior and thermal performance evaluation in a circular tube heat exchanger with the punched delta winglet vortex generators (PDWVG) inserted in the middle of the test section are presented. The effects of the flow attack angles that converging to the center of the tube; α = 0°, 5°, 10°, 15°, 20°, 25°, and flow directions; winglet tips pointing downstream and upstream, are investigated for the Reynolds numbers; Re = 100 – 2000. The finite volume method and SIMPLE algorithm are used for the current study. The results are presented… More >