Jing Yu¹, Jie Ren², Guangming Shen³, Weixiang Sun², Hui Wang^4,*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.9, pp. 2385-2398, 2023, DOI:10.32604/fdmp.2023.027877

Abstract In this paper, the influence of NaCl freeze-thaw (F-T) cycles and dry-wet (D-W) alternations on the flexural, compressive and bonding strengths of alkali-activated fly ash (FA) and a blast furnace slag powder (BFS) is investigated. The considered NaCl concentration is 3%. The effect of polypropylene fibers on the mechanical strengths is also examined. Scanning electron microscopy (SEM), thermogravimetry (TG) and X-ray diffraction (XRD) are selected to discern the mechanisms underpinning the NaCl-induced erosion. The obtained results indicate that the best results in terms of material resistance are obtained with admixtures containing 60% BFS and 40% FA in terms of mass… More >

Zhe Geng¹, Feng Feng¹, Shuzhen Zhang¹, Jie Li², Chengwei Liu³, Yang Li⁴, Tiantian Liu⁴, Suoying He^4,*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.9, pp. 2289-2304, 2023, DOI:10.32604/fdmp.2023.026707

Abstract Pre-cooling the inlet air of a dry cooling tower by means of a spray can improve the tower performance during periods of high temperature. To study the spray effect on the thermal performance of natural draft dry cooling towers (NDDCTs), in this study 3-D numerical simulations of such a process have been conducted using Fluent 16.2 (a two-way coupled Eulerian-Lagrangian approach). The considered NDDCT is 120 m high and only half system is simulated due to its structural symmetry. Three different spray strategies have been investigated at a typical crosswind speed of 4 m/s, which is the most frequent wind speed. The… More > Graphic Abstract

Mirmanto Mirmanto^a,*, Syahrul Syahrul^a, Agung Tri Wijayanta^b

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-5, 2023, DOI:10.5098/hmt.20.9

Abstract A study to examine the effect of evaporator diameters on the performances of a custom air-water generator had been conducted in naturally room air temperatures. Performances in this study consisted of fresh water production, coefficient of performance, and total heat transfer from the air. The freshwater was attained from the dew that dropped from the evaporator walls. It was from water vapour in the air that condensed due to the low temperature of the evaporator walls. The evaporator which had dimensions of 285 mm x 12.7 mm x 480 mm was placed in an open box (top and bottom). It… More >

Panpan Cao^1,2, Xiulin Huang^1,3,*, Shenxu Bao⁴, Jin Yang^5,*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.8, pp. 2041-2051, 2023, DOI:10.32604/fdmp.2023.027399

Abstract Using ethylene glycol monovinyl polyoxyethylene ether, 2-acrylamido-2-methylpropane sulfonic acid (AMPS) and acrylic acid as the main synthetic monomers, a high robustness polycarboxylate superplasticizer was prepared. The effects of initial temperature, ratio of acid to ether, amount of chain transfer agent, and synthesis process on the properties of the superplasticizer were studied. The molecular structure was characterized by GPC (Gel Permeation Chromatography) and IR (Infrared Spectrometer). As shown by the results, when the initial reaction temperature is 15°C, the ratio of acid to ether is 3.4:1 and the acrylic acid pre-neutralization is 15%, The AMPS substitution is 10%, the amount of… 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

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 0.4970∼0.5461, which corresponds to good… More >

Guoqing Long¹, Guogang Zhang¹, Qi Zhang², Cuilin Zhao², Suoying He^2,*, Fengzhong Sun²

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.7, pp. 1789-1801, 2023, DOI:10.32604/fdmp.2023.026559

Abstract In recent years, water collecting systems, with the associated advantages of energy saving and noise reduction, have become the foundation for the development of a scheme to optimize the structure of cooling towers. To explore the feasibility of this approach for mechanical draft cooling towers, a small-scale experimental device has been built to study the resistance and splash performances of three U-type water collecting devices (WCDs) for different water flow rates and wind speeds. The experimental results show that within the considered ranges of wind speed and water flow rate, the pressure drop of the different WCDs can vary significantly.… More > Graphic Abstract

Hongsha Xiao¹, Ruihan Zhang^2,*, Man Chen¹, Cui Jing¹, Shangjun Gao¹, Chao Chen¹, Huiyan Zhao¹, Xin Huang^2,*, Bo Kang³

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.7, pp. 1803-1815, 2023, DOI:10.32604/fdmp.2023.026143

Abstract The production performances of a well with a shale gas reservoir displaying a complex fracture network are simulated. In particular, a micro-seismic cloud diagram is used to describe the fracture network, and accordingly, a production model is introduced based on a multi-scale flow mechanism. A finite volume method is then exploited for the integration of the model equations. The effects of apparent permeability, conductivity, Langmuir volume, and bottom hole pressure on gas well production are studied accordingly. The simulation results show that ignoring the micro-scale flow mechanism of the shale gas leads to underestimating the well gas production. It is… More > Graphic Abstract

Ahmad S. Awad^1.*, Banan Hudaib², Waid Omar²

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.6, pp. 1535-1549, 2023, DOI:10.32604/fdmp.2023.024300

Abstract In this study, the potential of a low-cost bio-adsorbent, taken directly from Date Palm Trunk Fibers (DPTF) agricultural wastes, for cadmium ions removal from wastewaters is examined. The performances of this adsorbent are evaluated by building breakthrough curves at different bed heights and flow rates while keeping other parameters, such as the initial feed concentration, pH, and particle size, constant. The results indicate that the maximum cadmium adsorption capacity of DTPF can be obtained from the Thomas model as 51.5 mg/g with the most extended mass transfer zone of 83 min at the lowest flow rate at 5 ml/min. The… More > Graphic Abstract

Rachedi Khadraoui¹, Latra Boumaraf^1,*, Philippe Haberschill²

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.5, pp. 1115-1128, 2023, DOI:10.32604/fdmp.2022.022674

Abstract A theoretical investigation is presented about a double evaporator ejector refrigeration cycle (DEERC). Special attention is paid to take into account the influence of the sub-cooling and superheating effects induced by an internal heat exchanger (IHX). The ejector is introduced into the baseline cycle in order to mitigate the throttling process losses and increase the compressor suction pressure. Moreover, the IHX has the structure of a concentric counter-flow type heat exchanger and is intentionally used to ensure that the fluid at the compressor inlet is vapor. To assess accurately the influence of the IHX on the DEERC performance, a mathematical… More > Graphic Abstract

Anis Ammous^*, Ammar Alsaedi, Ahmed N. M. Alahmadi, Fahad Alharbi, Kaiçar Ammous

Computer Systems Science and Engineering, Vol.45, No.2, pp. 2171-2186, 2023, DOI:10.32604/csse.2023.029389

Abstract The Low Voltage Direct Current (LVDC) architecture gives higher benefits over the classic low-voltage alternating current (LVAC) supply concept. LVDC has fewer energy conversion stages, is compatible with renewable energy sources, and is easier to integrate with accumulators. In this paper, an LVDC supply concept is proposed and compared with currently used conventional photovoltaic (PV) systems in terms of efficiency. The new LVDC photovoltaic system behavior is validated using LTspice modeling tool. The findings of this work prove that the concept of LVDC supply is highly attractive when the electricity produced by the photovoltaic is used onsite in the daytime.… More >