Xin Ai^1,2,*, Mian Chen¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.3, pp. 661-670, 2024, DOI:10.32604/fdmp.2023.026819

Abstract

The efficient development and exploitation of shale oil depends on long-distance horizontal wells. As the degree of cleaning of the wellbore plays a key role in these processes, in this study, this problem is investigated experimentally by focusing on the dimensionless cuttings bed height. A method is proposed to calculate the horizontal-well hydraulic extension taking into account the influence of the wellbore cleaning degree on the wellbore pressure distribution and assess the effect of a variety of factors such as the bottom hole pressure, the circulating pressure drop, the drilling pump performance and the formation properties. The analysis shows that… More >

Fengping Li¹, Dong Sun^1,*, Qiaolin Zhang^1,2,3, Hairong Chen^1,2,3, István Bíró^2,3, Zhiyi Zheng⁴, Yaodong Gu^1,*

Molecular & Cellular Biomechanics, Vol.20, No.1, pp. 35-47, 2023, DOI:10.32604/mcb.2023.041016

Abstract Background: A children’s backpack is one of the important school supplies for school-age children. Long-term excessive weight can cause spinal deformity that cannot be reversed. This study compared a double helical spring decompression structure backpack (DHSB) with a traditional backpack (TB) to explore the optimization of decompression devices on upper body pressure. The finite element (FE) method was then used to explore the simulation of lumbar stress with different backpacks, in order to prove that DHSB can reduce the influence of backpack weight on lumbar vertebrae, avoid the occurrence of muscle discomfort and spinal deformity in children; Methods: 18 male… More > Graphic Abstract

Javed S. Shaikh^1,*, Krishna Kumar¹, Khizar A. Pathan², Sher A. Khan³

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.6, pp. 1637-1653, 2023, DOI:10.32604/fdmp.2023.025113

Abstract The complex fluid-dynamic instabilities and shock waves occurring along the surface of a two-dimensional wedge at high values of the Mach number are studied here through numerical solution of the governing equations. Moreover, a regression model is implemented to determine the pressure distribution for various Mach numbers and angles of incidence. The Mach number spans the interval from 1.5 to 12. The wedge angles (θ) are from 5° to 25°. The pressure ratio (P₂/P₁) is reported at various locations (x/L) along the 2D wedge. The results of the numerical simulations are compared with the regression model showing good agreement. More >

Xufeng Li^1,2,3, Yantao Bi^1,2,3,*

FDMP-Fluid Dynamics & Materials Processing, Vol.18, No.6, pp. 1699-1709, 2022, DOI:10.32604/fdmp.2022.019741

Abstract Using the conservation equations for mass, momentum and energy, a model is elaborated to describe the dynamics of high-energy gases in composite-perforation technological processes. The model includes a precise representation of the gunpowder combustion and related killing fluid displacement. Through numerical solution of such equations, the pressure distribution of the high-energy gas in fractures is obtained, and used to determine crack propagation. The accuracy of the model is verified by comparing the simulation results with actual measurements. More > Graphic Abstract

Jinbo Liu¹, Ziheng Jiang², Xuezhang Feng¹, Ruiquan Liao², Dianfang Feng¹, Xingkai Zhang^2,*, Hasimu Aikeremu¹

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.6, pp. 1243-1258, 2020, DOI:10.32604/fdmp.2020.010722

Abstract Laboratory experiments have been carried out to study the fluid flow in the wellbore of a horizontal gas well during the production process. The related pressure distribution has been determined considering different cases (different inflow media, different perforation opening methods and different liquid holdup). It has been found that the larger the fluid flow rate, the greater the pressure changes in the wellbore under the same hole opening mode. The uniformity of the perforation opening method was also an important factor affecting the magnitude of the wellbore pressure change. The liquid holdup also affected the pressure distribution, especially when the… More >

Lingzhi Yu¹, Yunqing Gu^1,*, Jiegang Mou¹, Denghao Wu¹, Zhenfu Chen², Yun Ren³

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.5, pp. 1007-1018, 2020, DOI:10.32604/fdmp.2020.09509

Abstract In order to improve the performances of a cycloid gerotor pump, the variations of the radial force induced by different rotating speeds and outlet pressures are analyzed numerically. Using the numerical simulations as a basis, an improved oil inlet and outlet groove structure is proposed. The results show that the radial force decreases with the decrease of the outlet pressure and of the rotor speed. Compared with the original model, the large-end oil inlet line and pressure line of the new oil groove are claw-shaped. This configuration can effectively weaken the pressure changes inside the gerotor pump and reduce accordingly… More >

Yuchi Kang^1,2, Meihong Liu¹, Sharon Kao‐Walter^2,3, Jinbin Liu¹, Qihong Cen⁴

Intelligent Automation & Soft Computing, Vol.25, No.2, pp. 405-411, 2019, DOI:10.31209/2019.100000102

Abstract A two-dimensional model of staggered tube banks of the bristle pack with different pitch ratios was solved by computational fluid dynamics (CFD). The pressure distribution along the gap centerlines and bristle surfaces were studied for different upstream pressure from 0.2 to 0.6MPa and models. The results show that the pressure is exponentially rather than strictly linearly decreasing distributed inside the bristle pack. The pressure distribution is symmetry about the circle’s horizontal line. The most obvious pressure drop occurred from about 60º to 90º. There is no stationary state reached between the kinetic energy and the static pressure when the upstream… More >

M. Tanaka^1,2, H. Noguchi¹, M. Fujikawa^3,4, M. Sato³, S. Oi³, T. Kobayashi³, K. Furuichi⁵, S. Ishimaru⁵, C. Nonomura⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.62, No.3, pp. 265-290, 2010, DOI:10.3970/cmes.2010.062.265

Abstract This paper describes the development of a proper constitutive model of woven fabrics and its implementation in nonlinear finite shell elements in order to simulate the large deformation behavior of cloth. This work currently focuses on a macroscopic continuum constitutive model that is capable of capturing the realistic mechanical behavior of cloth that is characterized by two families of yarns, i.e., warp and weft. In this study, two strategies are considered. One is a rebar layer model and the other is a polyconvex anisotropic hyperelastic material model. The latter avoids non-physical behavior and can consider the effect of the interaction… More >