Home / Journals / FDMP / Vol.17, No.5, 2021
Table of Content
  • Open Access

    ARTICLE

    Models for Predicting the Jet Trajectory and Intensity Drop Point of Fire Monitors

    Xiaojing Hou, Yongyou Cao*, Wenfeng Mao, Zheng Wang, Jiwu Yuan
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.5, pp. 859-869, 2021, DOI:10.32604/fdmp.2021.015967
    Abstract Two models are defined for predicting the trajectory of a foam jet originating from a fire monitor (hydrant) and the related intensity drop point. An experimental framework is also defined and used accordingly to compare real-time data with the predictions of such models. This mixed theoretical-experimental approach is proven to be effective for the determination of otherwise unknown coefficients which take into account several important factors such as the operation pressure, the elevation angle and the nozzle diameter. It is shown that the mean absolute error is smaller than 20%. More >

  • Open Access

    ARTICLE

    Effects of Particle Concentration on the Dynamics of a Single-Channel Sewage Pump under Low-Flow-Rate Conditions

    Peijian Zhou1,2, Chaoshou Yan3, Lingfeng Shu4, Hao Wang2, Jiegang Mou2,*
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.5, pp. 871-886, 2021, DOI:10.32604/fdmp.2021.012250
    Abstract Single-channel sewage pumps are generally used to transport solid-liquid two-phase media consisting of a fluid and solid particles due to the good non-clogging property of such devices. However, the non-axisymmetric structure of the impeller of this type of pumps generally induces flow asymmetry, oscillatory outflow during operations, and hydraulic imbalance. In severe cases, these effects can jeopardize the safety and stability of the overall pump. In the present study, such a problem is investigated in the framework of a Mixture multiphase flow method coupled with a RNG turbulence model used to determine the structure of the flow field and the… More >

  • Open Access

    ARTICLE

    Analysis of the Thermal Behavior of a Lithium Cell Undergoing Thermal Runaway

    Qifei Du1, Zhigang Fang2,3,*
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.5, pp. 887-898, 2021, DOI:10.32604/fdmp.2021.016265
    (This article belongs to this Special Issue: EFD and Heat Transfer III)
    Abstract This study examines the thermal runaway of a lithium ion battery caused by poor heat dissipation performances. The heat transfer process is analyzed on the basis of standard theoretical concepts. Water mist additives are considered as a tool to suppress the thermal runaway process. The ensuing behaviour of the battery in terms of surface temperature and heat generation is analyzed for different charge and discharge rates. It is found that when the remaining charge is 100%, the heat generation rate of the battery is the lowest, and the surface temperature with a 2C charge rate is higher than that obtained… More >

  • Open Access

    ARTICLE

    On Aircraft Lift and Drag Reduction Using V Shaped Riblets

    Zihai Geng1,2,*, Jinsheng Cai1, Yubiao Jiang1,2, Weiguo Zhang1,2
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.5, pp. 899-915, 2021, DOI:10.32604/fdmp.2021.012108
    (This article belongs to this Special Issue: EFD and Heat Transfer II)
    Abstract Reducing drag during take-off and nominal (cruise) conditions is a problem of fundamental importance in aeronautical engineering. Existing studies have demonstrated that v-shaped symmetrical riblets can effectively be used for turbulence control, with those with dimensionless depth h+ = 15 and dimensionless width s+ = 15 having the best drag reduction effect. In the present study, experimental tests have been conducted considering two models of the same size, one with smooth surface, the other with v-shaped riblets of the h+ = 15 and s+ = 15 type. The results show that for an angle of attack in the 8°~20° range… More >

  • Open Access

    ARTICLE

    A study on the Gas-based Lubrication of Elastic Foil Bearings Using an Over Relaxation Iteration Method

    Xiangxi Du*, Yanhua Sun
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.5, pp. 917-929, 2021, DOI:10.32604/fdmp.2021.015710
    (This article belongs to this Special Issue: EFD and Heat Transfer III)
    Abstract A new type of foil bearings with a specific surface microstructure is studied. First, relevant boundary conditions based on the assumption of rarefied gas flow are proposed, then, the static bearing capacity and friction torque are analyzed in the framework of a numerical technique based on the discretization of the governing equation for rarefied gas-dynamics. It is shown that under the same static load, the difference between the minimum film thickness calculated in this exploration and the results provided by dedicated tests is not obvious; with an increase in the load, the simulation results are closer to the test values;… More >

  • Open Access

    ARTICLE

    Visualization of Water Plugging Displacement with Foam/Gel Flooding in Internally Heterogeneous Reservoirs

    Jialiang Zhang1, Shumei He1, Tongjing Liu2,*, Tianlu Ni1, Jian Zhou2,3, Fang Huang1
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.5, pp. 931-946, 2021, DOI:10.32604/fdmp.2021.015638
    Abstract During the displacement of water plugging with binary flooding in internally heterogeneous reservoirs, it is essential to understand the distributions of remaining oil as well as the oil displacement mechanisms at different stages. In this study, two types of internally heterogeneous systems, i.e., vertical and horizontal wells are investigated experimentally through a microscopic approach. The results show that plugging agent types have a greater impact on oil recovery than well types, and foam injection can enhance oil recovery more effectively than gel injection. Additionally, the injection sequence of plugging agents significantly affects oil displacement efficiency. Injecting gel after foam is… More >

  • Open Access

    ARTICLE

    Experimental and Numerical Analysis of High-Strength Concrete Beams Including Steel Fibers and Large-Particle Recycled Coarse Aggregates

    Chunyang Liu1,2,*, Yangyang Wu1, Yingqi Gao1, Zhenyun Tang3
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.5, pp. 947-958, 2021, DOI:10.32604/fdmp.2021.016283
    Abstract In order to study the performances of high-strength concrete beams including steel fibers and large-particle recycled aggregates, four different beams have been designed, tested experimentally and simulated numerically. As varying parameters, the replacement rates of recycled coarse aggregates and CFRP (carbon fiber reinforced polymer) sheets have been considered. The failure mode of these beams, related load deflection curves, stirrup strain and shear capacity have been determined through monotonic loading tests. The simulations have been conducted using the ABAQUS finite element software. The results show that the shear failure mode of recycled concrete beams is similar to that of ordinary concrete… More >

  • Open Access

    ARTICLE

    Numerical Simulation and Experimental Analysis of the Influence of Asymmetric Pressure Conditions on the Splitting of a Gas-Liquid Two-Phase Flow at a T-Junction

    Lihui Ma1, Limin He1,2,*, Xiaoming Luo1,2, Xiangran Mi3
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.5, pp. 959-970, 2021, DOI:10.32604/fdmp.2021.016710
    (This article belongs to this Special Issue: Advanced Oil and Gas Transportation and Treatment Technologies)
    Abstract Dedicated experiments and numerical simulations have been conducted to investigate the splitting characteristics of a gas-liquid two phase flow at a T junction. The experiments were carried out for different gas-liquid velocities. The flow rates in the two branches were measured accurately to determine how the two considered phases distribute in the two outlets. The experimental results have shown that when the two outlet pressures are asymmetric, the two-phase flow always tends to flow into the outlet which has a lower pressure. As the inlet liquid velocity increases, however, the two-phase flow gradually tends to split evenly. Compared with the… More >

  • Open Access

    ARTICLE

    Influence of Electrical Field Distortions Induced by Water Droplets on the Contamination Characteristics of an Insulator

    Yukun Lv, Yuechi Wang*, Jiawen Wang
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.5, pp. 971-987, 2021, DOI:10.32604/fdmp.2021.016602
    Abstract When separated water droplets condense on the surface of a composite insulator, the electrical field on the insulator surface is distorted. In turn, such distortions change the trajectories of pollution particles. In this study, the COMSOL software is used to simulate such a process for the FXBW4-10/100 composite insulator with or without water droplets condensation under a 10 kV DC voltage. The influence of the wind speed and particles concentration on the contamination characteristics of the considered 110 kV insulator is analyzed. The results show that: 1) in the presence of water droplets on the insulator surface, the ratio of… More >

  • Open Access

    ARTICLE

    Investigation on the Changing Characteristics of Flow-Induced Noise in a Centrifugal Pump

    Guanpeng Li1, Lihui Sun2, Zhaoyang Wang1, Chunguo An1, Chang Guo3,*, Shen Cheng3, Ming Gao2,*
    FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.5, pp. 989-1001, 2021, DOI:10.32604/fdmp.2021.016507
    (This article belongs to this Special Issue: Recent Advances in Fluid Mechanics and Thermal Sciences)
    Abstract Centrifugal pumps are widely used in engineering for a variety of applications. A known drawback of these devices is the high-level noise generated during operations, which can affect their stability and adversely influence the entire working environment. By combining the Powell vortex sound theory, numerical simulations and experimental measurements, this research explores the trends of variation and the corresponding underlying mechanisms for the flow-induced noise at various locations and under different operating conditions. It is shown that the total sound source intensity (TSSI) and total sound pressure level (TSPL) in the impeller, in the region between the inlet to the… More >

Share Link

WeChat scan