Nannan Liu^*, Hengchen Qi, Hui Xu, Yanfeng He

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.8, pp. 1731-1741, 2024, DOI:10.32604/fdmp.2024.048354 - 06 August 2024

Abstract Low salinity water containing sulfate ions can significantly alter the surface wettability of carbonate rocks. Nevertheless, the impact of sulfate concentration on the desorption of oil film on the surface of carbonate rock is still unknown. This study examines the variations in the wettability of the surface of carbonate rocks in solutions containing varying amounts of sodium sulfate and pure water. The problem is addressed in the framework of molecular dynamics simulation (Material Studio software) and experiments. The experiment’s findings demonstrate that sodium sulfate can increase the rate at which oil moisture is turned into More > Graphic Abstract

Nan Liu^1,2, Chen Hong^3,4,5, Xinchao Su^3,4,5, Xing Jin^1,2, Chen Jiang^3,4,5,*, Yuqi Shi^1,2, Bingkun Wang^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.8, pp. 1867-1882, 2024, DOI:10.32604/fdmp.2024.047427 - 06 August 2024

Abstract As the velocity of a train increases, the corresponding air pumping power consumption of the brake discs increases proportionally. In the present experimental study, a standard axle-mounted brake disc with circumferential pillars was analyzed using a 1:1 scale model and a test rig in a wind tunnel. In particular, three upstream velocities were selected on the basis of earlier investigations of trains operating at 160, 250, and 400 km/h, respectively. Moreover, 3D steady computational fluid dynamics (CFD) simulations of the flow field were conducted to compare with the wind tunnel test outcomes. The results for More >

Lihui Ma^1,*, Zhuo Han¹, Wei Li¹, Guangfeng Qi¹, Ran Cheng², Yuanyuan Wang¹, Xiangran Mi³, Xiaohan Zhang¹, Yunfei Li¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.6, pp. 1381-1392, 2024, DOI:10.32604/fdmp.2024.046405 - 27 June 2024

Abstract When a gas-liquid two-phase flow (GLTPF) enters a parallel separator through a T-junction, it generally splits unevenly. This phenomenon can seriously affect the operation efficiency and safety of the equipment located downstream. In order to investigate these aspects and, more specifically, the so-called bias phenomenon (all gas and liquid flowing to one pipe, while the other pipe is a liquid column that fluctuates up and down), laboratory experiments were carried out by using a T-junction connected to two parallel vertical pipes. Moreover, a GLTPF prediction model based on the principle of minimum potential energy was… More >

Xiao Sun¹, Jiangbo Tong¹, Yuliang Zhang^2,*, Haibing Cai³, Wen Zhou⁴, Xiaoqi Jia⁵, Litao Ou⁶

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.4, pp. 725-737, 2024, DOI:10.32604/fdmp.2023.045541 - 28 March 2024

Abstract Centrifugal pumps are widely used in the metallurgy, coal, and building sectors. In order to study the hydraulic characteristics of a closed impeller centrifugal pump during its shutdown in the so-called power frequency and frequency conversion modes, experiments were carried to determine the characteristic evolution of parameters such as speed, inlet and outlet pressure, head, flow rate and shaft power. A quasi-steady-state method was also used to further investigate these transient behaviors. The results show that, compared to the power frequency input, the performance parameter curves for the frequency conversion input are less volatile and More >

Yun Lei^1,2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.12, pp. 3021-3032, 2023, DOI:10.32604/fdmp.2023.029570 - 27 October 2023

Abstract The highly inefficient simultaneous extraction of coal and gas from low-permeability and high-gas coal seams in deep mines is a major problem often restricting the sustainable development of coal industry. A possible way to solve this problem under deep and complex geological conditions is represented by the technology based on the phase-change induced explosion of liquid carbon dioxide. In this work, the mechanism of formation of the coal mass fracture circle resulting from the gas cracking process is theoretically analyzed. Numerical simulations show that a blasting crushing zone with a radius of 1.0 m is More >

Ummid I. Shaikh^a , Sonali Kale^b, Anirban Sur^c, Anindita Roy^c

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-10, 2023, DOI:10.5098/hmt.20.28

Abstract The requirement for sustainable development for buildings is to have environmentally friendly cooling and heating systems. The utilization of phase change materials (PCM) in the cooling system is a potential solution for minimizing active power requirements as well as for reducing the size of components of a vapor compression refrigeration VCR system. A prototype of an Air-PCM (T25™) heat exchanger was fabricated and tested in actual environmental conditions. Experimental trials using a salt hydrate as PCM have shown the maximum cooling effect of 2.05 kW when 75% of the PCM was solidified. Based on the More >

Ameer Abed Jaddoa^* , Karema Assi Hamad, Arshad Abdul Jaleil Hameed

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-9, 2023, DOI:10.5098/hmt.20.18

Abstract In the Heat Transfer process, many innovations were introduced aiming to obtain the most optimum behavior of the cooling process using nanofluids as coolant liquids. These nanofluids have gained much attention in cooling systems due to their special rheological and thermal performance. In this work, an experimental evaluation is conducted for nanofluids Al₂O₃, SiO₂, CuO, ZnO, and TiO₂ nanoparticles applied to a mini-channel. The nanofluid particles were entirely spread out in purified water (size of 15 nm) before being passed to the heat sink through a confined inflow channel. The obtained results showed that the achieved improvement… More >

Daoming Shen^1,*, Jinhong Xia¹, Chao Gui¹, Songtao Xue²

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.6, pp. 1411-1424, 2023, DOI:10.32604/fdmp.2023.024924 - 30 January 2023

Abstract The thermal transmission coefficient for a micro-ribbed tube has been determined using theoretical relationships and the outcomes of such calculations have been compared with experiments conducted using a R1234yf refrigerant undergoing condensation. In particular four theoretical single-phase flow and three multi-phase flow models have been used in this regard. The experimental results show that: the Oliver et al. criterion equation overestimates the experimental results as its accuracy is significantly affected by the specific conditions realized inside micro-fin tubes; the Miyara et al. criterion equation prediction error is less than 15%; the Cavallini et al. approach More >

Li Luo¹, Yuhang Fan¹, Yu Wang¹, Peiyong Ni¹, Xuewen Zhang¹, Guannan Xi^2,*

Energy Engineering, Vol.120, No.1, pp. 125-145, 2023, DOI:10.32604/ee.2022.022295 - 27 October 2022

Abstract This paper aims to design a special exchanger to recover the exhaust gas heat of marine diesel engines used in small and medium-sized fishing vessels, which can then be used to heat water up to 55°C–85°C for membrane desalination devices to produce fresh water. A new exhaust-gas heat exchanger of fins and tube, with a reinforced heat transfer tube section, unequal spacing fins, a mixing zone between the fin groups and four routes tube bundle, was designed. Numerical simulations were also used to provide reference information for structural design. Experiments were carried out for exhaust… More >

Chun Ye^1,2,3, Jingjing Gao^1,2,3, Zhihui Wang^1,2,3, Weibiao Zheng^1,2,3, Yibei Wang^2,4, Xingkai Zhang^1,2,3,*, Ming Liu⁵

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.3, pp. 755-766, 2023, DOI:10.32604/fdmp.2022.021868 - 29 September 2022

Abstract The response of an adjustable critical-flow Venturi nozzle is investigated through a set indoor experiments aimed to determine the related critical flow rate, critical pressure ratio, and discharge coefficient. The effect of a variation in the cone displacement and liquid content on the critical flow characteristics is examined in detail and it is shown that the former can be used to effectively adjust the critical flow rate. The critical pressure ratio of the considered nozzle is above 0.85, and the critical flow control deviation of the gas flow is within ±3%. Liquid flow can reduce More >