Open Access
ARTICLE
Khadija A. Al-Hassani1, M. S. Alam2, M. M. Rahman1,*
FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.1, pp. 1-20, 2021, DOI:10.32604/fdmp.2021.013497
Abstract Nanofluids have enjoyed a widespread use in many technological applications due to their peculiar properties. Numerical simulations are presented about the unsteady behavior of mixed convection of Fe3O4-water, Fe3O4- kerosene, Fe3O4-ethylene glycol, and Fe3O4-engine oil nanofluids inside a lid-driven triangular cavity. In particular, a two-component non-homogeneous nanofluid model is used. The bottom wall of the enclosure is insulated, whereas the inclined wall is kept a constant (cold) temperature and various temperature laws are assumed for the vertical wall, namely: θ = 1(Case 1), θ = Y(1 – Y)(Case 2), and θ = sin(2πY)(Case 3). A tilted magnetic field of uniform… More >
Open Access
ARTICLE
Daoming Shen1,*, Xia Zhang2, Jinhong Xia1, Shunqun Li3
FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.1, pp. 21-37, 2021, DOI:10.32604/fdmp.2021.010767
Abstract The freezing of soil containing a liquid is a complex transient heat conduction problem involving phase change and release or absorption of latent heat. Existing efforts have essentially focused on theoretical research and numerical simulations. In the present study, the problem is approached from an experimental point of view using the so-called “freezing model test” method. In particular, in order to establish a precise relationship between the model and the prototype, a temperature similarity criterion is derived using the condition of an equal number of Kosovitch. Similarity is also established with respect to other aspects. A similarity criterion for the… More >
Open Access
ARTICLE
Sheng Bai, Feng Bao*, Fengzhi Zhao
FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.1, pp. 39-47, 2021, DOI:10.32604/fdmp.2021.010376
Abstract The present study aims to improve the efficiency of typical procedures used for post-processing flow field data by applying a neural-network technology. Assuming a problem of aircraft design as the workhorse, a regression calculation model for processing the flow data of a FCN-VGG19 aircraft is elaborated based on VGGNet (Visual Geometry Group Net) and FCN (Fully Convolutional Network) techniques. As shown by the results, the model displays a strong fitting ability, and there is almost no over-fitting in training. Moreover, the model has good accuracy and convergence. For different input data and different grids, the model basically achieves convergence, showing… More >
Open Access
ARTICLE
Ling Cheng1,2,3,*, Bingqing Guo1,2, Kecheng Li1,2
FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.1, pp. 49-70, 2021, DOI:10.32604/fdmp.2021.011062
(This article belongs to this Special Issue: The Progress in Building Indoor Air Quality: Indoor Airflow and Pollutant Control)
Abstract The performances of a hybrid energy system for decentralized heating are investigated. The proposed energy system consists of a solar collector, an air-source heat pump, a gas-fired boiler and a hot water tank. A mathematical model is developed to predict the operating characteristics of the system. The simulation results are compared with experimental data. Such a comparison indicates that the model accuracy is sufficient. The influence of the flat plate solar collector area on the economic and energy efficiency of such system is also evaluated through numerical simulations. Finally, this system is optimized using the method of orthogonal design. The… More >
Open Access
ARTICLE
Shidan Chi1, Tao Luan1,*, Yan Liang2, Xundong Hu2, Yan Gao3,*
FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.1, pp. 71-80, 2021, DOI:10.32604/fdmp.2021.013178
(This article belongs to this Special Issue: Recent Advances in Fluid Mechanics and Thermal Sciences)
Abstract Improving the primary steam parameters is one of the most direct ways to improve the cycle efficiency of a power generation system. In the present study, the typical problem connected to the excessively high superheat degree of extraction steam in an ultra-supercritical (USC) double-reheat unit is considered. Using a 1000 MW power plant as an example, two systems (case 1 and case 2) are proposed, both working in combination with a regenerative steam turbine. The thermal performances of these two systems are compared with that of the original system through a heat balance method and an exergy balance strategy. The… More >
Open Access
ARTICLE
Ke Sun, Xiaoyu Hu, Da Li, Guodong Zhang, Kui Zhao, Haiyang Zhao, Shuzhan Bai*
FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.1, pp. 81-95, 2021, DOI:10.32604/fdmp.2021.013895
(This article belongs to this Special Issue: Recent Advances in Fluid Mechanics and Thermal Sciences)
Abstract Experiments on subcooled flow boiling have been conducted using water in a rectangular flow channel. Similar to the coolant channel in internal combustion engines (IC engines), the flow channel in this experiment was asymmetrically heated. Bubble images were captured using a high speed camera from the side view of the channel. The experimental conditions in terms of bulk temperature, bulk velocity, pressure and heat flux ranged from 65°C–75°C, 0.25 m/s–0.75 m/s, 1–1.7 bar and 490 kW/m2–700 kW/m2, respectively. On the basis of these tests, a statistical analysis of the bubble size has been conducted considering a population of 1400 samples.… More >
Open Access
ARTICLE
Ming Liu1,2,3, Xingkai Zhang1,4, Dong Wang1,*
FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.1, pp. 97-107, 2021, DOI:10.32604/fdmp.2021.011292
Abstract The mechanically choked orifice plate (MCOP) is a new type of device for flow control by which choking conditions for incompressible fluids can be obtained with relatively small pressure losses. Given the lack of relevant results and data in the literature, in the present study, we concentrate on the experimental determination of the flow coefficient for the annular orifice, the pressure distribution in the MCOP, and the characteristics of the choked flow itself. As confirmed by the experimental results, the Reynolds number, the orifice plate thickness, the plug taper, and the eccentricity have an obvious influence on the aforementioned flow… More >
Open Access
ARTICLE
Taidong Xu1,2, Hao Liu2, Dejun Zhang1,2, Yadong Li2, Xiaoming Zhou2,*
FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.1, pp. 109-121, 2021, DOI:10.32604/fdmp.2021.010608
(This article belongs to this Special Issue: Bioheat Transfer in Micro and Macro Scales)
Abstract With the progressive increase in the number of transistors that can be accommodated on a single integrated circuit, new strategies are needed to extract heat from these devices in an efficient way. In this regard methods based on the combination of the so-called “jet impingement” and “micro-channel” approaches seem extremely promising for possible improvement and future applications in electronics as well as the aerospace and biomedical fields. In this paper, a hybrid heat sink based on these two technologies is analysed in the frame of an integrated model. Dedicated CFD simulation of the coupled flow/temperature fields and orthogonal tests are… More >
Open Access
ARTICLE
Mengyuan Cao, Yi Xu*, Yilin Dong
FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.1, pp. 123-139, 2021, DOI:10.32604/fdmp.2021.011443
(This article belongs to this Special Issue: Bioheat Transfer in Micro and Macro Scales)
Abstract The damage caused by thermal stress during rewarming vitrified biosamples is one of the major obstacles for clinical purposes. Magnetic warming is a highly effective approach to overcome this hurdle and can achieve rapid and spatially homogeneous heating. The current research investigates the effects of magnetic warming on the histological and biomechanical properties of the vitrified umbilical arteries (UAs) through experiments and simulation. The results of experiments show that, for the case of magnetic warming comparing with the conventional water bath, magnetic warming presents better preservation of extracellular matrix (ECM), collagen fibers, elastic fibers, and muscle fibers of the umbilical… More >
Open Access
ARTICLE
Siqi Liu1,2,3, Guanqi Huang3,4,*
FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.1, pp. 141-157, 2021, DOI:10.32604/fdmp.2021.011990
(This article belongs to this Special Issue: EFD and Heat Transfer II)
Abstract Many countries in the world have experienced extremely rapid urbanization during recent decades. The rapid development of densely populated areas has produced many urban environmental problems. This research explores the relationship between urban morphology and ventilation conditions. Through 3D modeling and Computational Fluid Dynamics (CFD) simulation, we focus on the large scale ventilation of an extended area with several buildings. As a testbed, in particular, the core part of Kwun Tong industrial park in Hong Kong is examined, and in order to validate the approach, 10 measurement points are used to get experimental values to be used for comparison (such… More >
Open Access
ARTICLE
Liying Zhou1,2, Yu Liang2,*
FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.1, pp. 159-170, 2021, DOI:10.32604/fdmp.2021.010051
(This article belongs to this Special Issue: EFD and Heat Transfer II)
Abstract The use of ethanol is a promising method to reduce the emissions of diesel engines. The present study has been based on the installation of a gasoline electronic injection system in a single-cylinder diesel engine to control the amount of ethanol entering the cylinder during the compression (while diesel has been injected into the cylinder by the original pump injection system). The injection time has been controlled by crank angle signal collected by an AVL angle indicator. In the tests ethanol and diesel each accounted for half of the fuel volume, and the total heat energy supply of the fuel… More >
Open Access
ARTICLE
Mohamad Shukri Zakaria1,*, Haslina Abdullah2, Azmi Nordin1, Syazwati Ahmad Zaki1
FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.1, pp. 171-179, 2021, DOI:10.32604/fdmp.2021.010974
(This article belongs to this Special Issue: Fluid Structure Interaction in Various Engineering Field)
Abstract This study deals with the interaction of blood flow with the wall aorta, i.e., the boundary of the main artery that transports blood in the human body. The problem is addressed in the framework of computational fluid dynamics complemented with (FSI), i.e., a fluid-structure interaction model. Two fundamental types of wall are considered, namely a flexible and a rigid boundary. The resulting hemodynamic flows are carefully compared in order to determine which boundary condition is more effective in reproducing reality. Special attention is paid to wall shear stress (WSS), a factor known for its ability to produce atherosclerosis and bulges.… More >
Open Access
ARTICLE
Yuhang Long1, Jingyi Wang2,*
FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.1, pp. 181-187, 2021, DOI:10.32604/fdmp.2021.011185
(This article belongs to this Special Issue: Fluid Mechanics and Green Material Processing)
Abstract This study considers P.O42.5 cement from different sources and evaluates the related surplus coefficient (defined as the proportionality factor linking the measured compressive strength value of the cement after 28 days to the “standard” value of cement strength). The needed tests have been conducted using a mixer, a pressure testing machine, a flexural testing machine, a vibrating table a ramming rod, a feeder and a metal ruler. The average value of the measured cement strength surplus coefficient of cement produced by five distinct cement manufacturers has been found to be 1.16. These results can be used as the basis to… More >
Open Access
ARTICLE
Yu Zhou1,*, Shen Ji2,*
FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.1, pp. 189-200, 2021, DOI:10.32604/fdmp.2021.011744
Abstract The outbreak of Corona Virus (COVID-19) has spread over a large number of countries. The virus is typically transported inside liquid droplets produced by human beings. As a result, doctors operating in the consulting rooms of hospitals are potentially exposed to high risk. Taking into account the evaporation of droplets and using a hybrid Eulerian-Lagrangian framework to determine the airflow pattern and corresponding motion of droplets, in the present study, the motion of droplets is investigated with regard to the situation in which doctors check patients in front of their bed. A turbulence model (RNG k-ɛ) is used. The purification… More >
Open Access
ARTICLE
Senchun Miao1,2,*, Hongbiao Zhang1, Fengxia Shi1, Xiaohui Wang1, Xijin Ma1
FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.1, pp. 201-214, 2021, DOI:10.32604/fdmp.2021.012950
Abstract A volute is a curved funnel with cross-sectional area increasing towards the discharge port. The volute of a centrifugal pump is the casing hosting the fluid being pumped by the impeller. In Pump-as-turbine devices (PAT), vice versa the volute plays the role of energy conversion element. In the present analysis, this process is analyzed using CFD. The results show that in the contraction section of volute the conversion between dynamic pressure energy and static pressure energy essentially depends on the reduction of flow area, while in the spiral section, frictional losses also play a significant role. From the throat to… More >
Open Access
ARTICLE
Qinghua Wang1, Junzheng Yang1, Wei Luo2,*
FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.1, pp. 215-233, 2021, DOI:10.32604/fdmp.2021.011914
Abstract Well completions are generally used to connect a reservoir to the surface so that fluids can be produced from or injected into it. With these systems, pipe flows are typically established in the horizontal sections of slotted screen completions and inflow control device (ICD) completions; moreover, an annular flow exists in the region between the pipe and the borehole wall. On the basis of the principles of mass and momentum conservation, in the present study, a coupling model considering the variable mass flow of the central tubing, the variable mass flow of the annular tubing and the reservoir seepage is… More >