Fang Jin^*, Dong Zhou, Liying Zhu

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.2, pp. 285-302, 2022, DOI:10.32604/fdmp.2022.017593

Abstract The purpose is to study the microstructure and macroscopic fluid-dynamic behavior of soft soil after it has been subjected to a seepage consolidation procedure. First, the microscopic pore structure of soft clay is quantitatively studied by a scanning electron microscope technique. Second, the average contact area rate of soil particles is obtained employing statistical analysis applied to microscopic images of soft soil, and the macroscopic porosity of soft clay is determined through an indoor geotechnical test. Finally, mathematical relationships are introduced by fitting the results of the test. The results show that the unmodified empirical equation for the permeability coefficient… More >

Yueli Feng^1,2, Yuetian Liu^1,2,*, Xiaolong Mao^1,2, Jian Chen^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.2, pp. 371-393, 2022, DOI:10.32604/fdmp.2022.017534

Abstract This study clarifies the seepage characteristics of complex fractured pressure-sensitive reservoirs, and addresses a common technological problem, that is the alteration of the permeability degree of the reservoir bed (known to be responsible for changes in the direction and velocity of fluid flows between wells). On the basis of a new pressure-sensitive equation that considers the fracture directional pressure-sensitive effect, an oil-gas-water three-phase seepage mathematical model is introduced, which can be applied to pressure-sensitive, full-tensor permeability, ultralow-permeability reservoirs with fracture-induced anisotropy. Accordingly, numerical simulations are conducted to explore the seepage laws for ultralow-permeability reservoirs. The results show that element patterns… More >

Jiawei Shi¹, Shuai Ge¹, Xiaozhen Sheng^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.2, pp. 463-480, 2022, DOI:10.32604/fdmp.2022.017508

Abstract In order to understand the mechanism by which a pantograph can generate aerodynamic noise and grasp its far-field characteristics, a simplified double-strip pantograph is analyzed numerically. Firstly, the unsteady flow field around the pantograph is simulated in the frame of a large eddy simulation (LES) technique. Then the location of the main noise source is determined using surface fluctuating pressure data and the vortex structures in the pantograph flow field are analyzed by means of the Q-criterion. Based on this, the relationship between the wake vortex and the intensity of the aerodynamic sound source on the pantograph surface is discussed.… More >

Jian Song^*

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.2, pp. 345-354, 2022, DOI:10.32604/fdmp.2022.017382

Abstract Computational Fluid Dynamics is used to assess the thermal (heat transfer) performances of an automobile engine considering different grille opening and closing degrees. For this purpose the entire vehicle is modelled and three fundamental aspects are examined, namely, the open area of the air intake grille, the position of the upper and lower grilles and their shape. The results show that the opening area and position of the grille have some influence also on the aerodynamic characteristics of the automobile. With an increase in the opening angle of the grille, the C_D (Drag Coefficient) value of the whole vehicle becomes… More >

Jianhui Yang¹, Kai Shen¹, Shoudong Pan², Shuren Wang^3,*, Zhengsheng Zou³

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.2, pp. 243-255, 2022, DOI:10.32604/fdmp.2022.016677

Abstract The large deformation of soft rock tunnel is one of the key problems to be overcome in the tunnel construction stage. In the present study, the deformation mechanism of a representative tunnel and some related countermeasures are investigated using field tests and engineering geological analysis. Owing to the scarce performances of methods based on other criteria such as small pipe spacing, anchor bolt length and steel frame spacing, a new support scheme is implemented and optimized. Results show that shear failure and bedding sliding are produced under high horizontal stress conditions. The low strength of the surrounding rock results in… More >

Xiangxi Du^1,*, Muyun Liu², Yanhua Sun¹

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.2, pp. 303-312, 2022, DOI:10.32604/fdmp.2022.016242

Abstract The computational fluid dynamics (CFD) technology is analyzed and calculated utilizing the turbulence model and multiphase flow model to explore the performance of internal circulating fluidized beds (ICFB) based on CFD. The three-dimensional simulation method can study the hydrodynamic properties of the ICFB, and the performance of the fluidized bed is optimized. The fluidization performance of the ICFB is improved through the experimental study of the cross-shaped baffle. Then, through the cross-shaped baffle and funnel-shaped baffle placement, the fluidized bed reaches a coupled optimization. The results show that CFD simulation technology can effectively improve the mass transfer efficiency and performance… More >

Wei Chen^1,2, Zhaofeng Guo^3,4,*, Hongda Feng^3,4, Sheng Hu^1,2, Ling Lu^1,2, Chuanmin Chen^3,4, Xiaowen Wu^1,2, Hao Cao^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.2, pp. 481-496, 2022, DOI:10.32604/fdmp.2022.015746

Abstract This study investigates a dual-cavity resonant composite sound-absorbing structure based on a micro-perforated plate. Using the COMSOL impedance tube model, the effects of various structural parameters on sound absorption and sound insulation performances are analyzed. Results show that the aperture of the micro-perforated plate has the greatest influence on the sound absorption coefficient; the smaller the aperture, the greater is this coefficient. The thickness of the resonance plate has the most significant influence on the sound insulation and resonance frequency; the greater the thickness, the wider the frequency domain in which sound insulation is obtained. In addition, the effect of… More >

Dmitrii Kuzmenkov^1,*, Pavel Struchalin^1,2, Yulia Litvintsova¹, Maksim Delov¹, Vladimir Skrytnyy¹, Kirill Kutsenko¹

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.1, pp. 1-14, 2022, DOI:10.32604/fdmp.2022.018526

Abstract

Nanofluids have great potential for solar energy harvesting due to their suitable optical and thermophysical properties. One of the promising applications of nanofluids is utilization in solar collectors with the direct absorption of light (DASC). The design of a DASC requires detailed knowledge of the optical properties of nanofluids, which can be significantly affected by the particle size distribution. The paper presents the method to take into account the particle size distribution when calculating nanofluid extinction spectra. To validate the proposed model, the particle size distribution and spectral absorbance were measured for aqueous suspension with multi-walled graphite nanotubes; the minimum… More >

Xiao Wu^1,*, Zhaoting Wang¹, Mei Dong², Longfei Dong¹, Quan Ge¹

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.1, pp. 145-158, 2022, DOI:10.32604/fdmp.2022.018227

Abstract Liquefied natural gas (LNG) is an important energy source and occupies an important proportion in natural gas consumption, therefore, the selection of appropriate liquefaction processes and related optimization should be seen as subjects of great importance. Accordingly, in the present review, we provide a comparative and critical analysis of the current status of natural gas liquefaction technology through examination of the advantages and disadvantages associated with three natural gas liquefaction processes (namely, the cascade liquefaction cycle, the expander-based cycle and the mixed refrigerant cycle). It is shown that the energy consumption related to the cascade refrigeration cycle is the lowest.… More >

Shaohua Zhai¹, Guannan Xi^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.1, pp. 109-130, 2022, DOI:10.32604/fdmp.2022.018186

Abstract In order to study the effect of different gap ratios on the thermofluid-dynamic field around a bluff body located in proximity to a heated wall, a series of experiments and numerical simulations have been conducted. The former were carried out using an open circulating water tank experimental platform and a single cylinder and square column as geometrical models (their characteristic length being D). The latter were based on the well-known SIMPLE algorithm for incompressible flow. The results show that the gap ratio is an important factor affecting the wake characteristics of near-wall bluff bodies. When the gap ratio is small,… More >