Qing Wang^*, Haige Wang, Hongchun Huang, Lubin Zhuo, Guodong Ji

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.10, pp. 2569-2578, 2023, DOI:10.32604/fdmp.2023.025349

Abstract Sticking is the most serious cause of failure in complex drilling operations. In the present work a novel “early warning” method based on an artificial intelligence algorithm is proposed to overcome some of the known problems associated with existing sticking-identification technologies. The method is tested against a practical case study (Southern Sichuan shale gas drilling operations). It is shown that the twelve sets of sticking fault diagnostic results obtained from a simulation are all consistent with the actual downhole state; furthermore, the results from four groups of verification samples are also consistent with the actual downhole state. This shows that… More >

Qunyi Wang¹, Xiaoli Ma¹, Yongbin Bi¹, Haiyan He¹, Xiao Gu¹, Tongjing Liu^2,*, Lekun Zhao³

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.2, pp. 361-377, 2023, DOI:10.32604/fdmp.2022.020358

Abstract Current methods for the analysis of channeling-path phenomena in reservoirs cannot account for the influence of time and space on the actual seepage behavior. In the present study, this problem is addressed considering actual production data and dynamic characteristic parameters quantitatively determined in the near wellbore area by fitting the water-cut curve of the well. Starting from the dynamic relationship between injection and production data, the average permeability is determined and used to obtain a real-time quantitative characterization of the seepage behavior of the channeling-path in the far wellbore area. For the considered case study (Jidong oilfield), it is found… More >

Abdulsattar Abdullah Hamad¹, Ahmed S. Al-Obeidi², Enas H. Al-Taiy², Osamah Ibrahim Khalaf³, Dac-Nhuong Le^4,5,*

CMC-Computers, Materials & Continua, Vol.66, No.3, pp. 3311-3327, 2021, DOI:10.32604/cmc.2021.013395

Abstract Synchronization is one of the most important characteristics of dynamic systems. For this paper, the authors obtained results for the nonlinear systems controller for the custom Synchronization of two 4D systems. The findings have allowed authors to develop two analytical approaches using the second Lyapunov (Lyp) method and the Gardano method. Since the Gardano method does not involve the development of special positive Lyp functions, it is very efficient and convenient to achieve excessive system SYCR phenomena. Error is overcome by using Gardano and overcoming some problems in Lyp. Thus we get a great investigation into the convergence of error… More >

Yuli D. Chashechkin^*

FDMP-Fluid Dynamics & Materials Processing, Vol.16, No.4, pp. 773-800, 2020, DOI:10.32604/fdmp.2020.09001

Abstract The structure of the flow and the acoustic signals generated by the impact of a freely falling drop of water with an underlying quiescent fluid have been investigated for droplets having diameter 0.5 cm and a contact velocity in the range 1.5 < U < 5 m/s. The experimental study has been supported by high-resolution videos of the flow (as seen from above and from the side). The evolution of ejecta, spikes, droplets spray, cavity, splash, secondary cavity, streamer, secondary droplets and sequence of capillary waves is reported accordingly. In particular, perturbations of the smoothed free surface with transverse dimensions… More >

Congcong Wang^{1, 2, 3}, Pengyu Liu^{1, 2, 3, *}, Kebin Jia^{1, 2, 3}, Xiaowei Jia⁴, Yaoyao Li^{1, 2, 3}

CMC-Computers, Materials & Continua, Vol.64, No.3, pp. 2043-2055, 2020, DOI:10.32604/cmc.2020.010505

Abstract Weather phenomenon recognition plays an important role in the field of meteorology. Nowadays, weather radars and weathers sensor have been widely used for weather recognition. However, given the high cost in deploying and maintaining the devices, it is difficult to apply them to intensive weather phenomenon recognition. Moreover, advanced machine learning models such as Convolutional Neural Networks (CNNs) have shown a lot of promise in meteorology, but these models also require intensive computation and large memory, which make it difficult to use them in reality. In practice, lightweight models are often used to solve such problems. However, lightweight models often… More >

Peter L. Bishay¹, Satya N. Atluri¹

CMC-Computers, Materials & Continua, Vol.33, No.1, pp. 19-62, 2013, DOI:10.3970/cmc.2013.033.019

Abstract In this paper, 2D and 3D Multiphysics Voronoi Cells (MVCs) are developed, for the Direct Mesoscale Numerical Simulation (DMNS) of the switching phenomena in ferroelectric polycrystalline materials. These arbitrarily shaped MVCs (arbitrary polygons in 2D, and arbitrary polyhedrons in 3D with each face being an arbitrary polygon) are developed, based on assuming radial basis functions to represent the internal primal variables (mechanical displacements and electric potential), and assuming linear functions to represent the primal variables on the element boundaries. For the 3D case, the linear functions used to represent the primal variables on each of the polygonal surfaces of the… More >

S. Torii¹

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.3, pp. 257-268, 2004, DOI:10.3970/cmes.2004.005.257

Abstract A numerical study is performed to investigate the thermal fluid-flow transport phenomena in the concentric annulus with a slightly heated rotating inner core moving in the flow direction and a stationary insulated outer cylinder. Emphasis is placed on the effects of the axial rotation and streamwise movement of inner core on the flow structure and heat transfer performance. A k-ε turbulence model is employed to determine the turbulent viscosity and the turbulent kinetic energy. The turbulent heat flux is expressed by Boussinesq approximation in which the eddy diffusivity for heat is determined using two-equation heat transfer model. The governing equations… More >

Janusz Badur, MichaA, Karcz, Marcin LemaA"ski, Lucjan NastaA,ek

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.3, pp. 91-92, 2011, DOI:10.3970/icces.2011.019.091

Abstract Due to last mass flow rate measurements in gas micro and nano-channels several discrepancies in the mathematical modeling have been arise. The most important one, is the "flow enhancement" related with the wall slip phenomena. Thus, in the literature, there is opinion that the Navier-Stokes slip condition is correct only in certain restricted circumstances, particularly those restricted to the first order boundary conditions. A one possible way for solving of the above discrepancies, used recently in the literature, is developing a variety of so-called ßecond order boundary conditions". This way is incorrect since it always leads to an inconsistency between… More >

A.P.S. Selvadurai¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.15, No.2, pp. 57-64, 2010, DOI:10.3970/icces.2010.015.057

Abstract This paper examines the problem of the internal heating of a poroelastic halfspace by an embedded rigid disc inclusion. A computational approach is adopted for modelling the resulting coupled thermo-hydro mechanical processes associated with the heating by the disc inclusion. More >

T. Nishioka¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.1, No.3, pp. 105-112, 2007, DOI:10.3970/icces.2007.001.105

Abstract This paper summarizes recent discovery for the Governing Condition of Dynamic Crack Bifurcation Phenomena, which were found by the author's laboratory. More >