scholarly journals Effect of Pulsed Jet on Pore Pressure of Deep Formation Rock

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Yong Wang ◽  
Hongjian Ni ◽  
Ruihe Wang ◽  
Peng Lei ◽  
Bin Huang ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Linear Relationship ◽  
Pore Pressure ◽  
Negative Pressure ◽  
Pulse Amplitude ◽  
Pulse Frequency ◽  
Maximum Point ◽  
The Finite Element Method ◽  
Pulsed Jet

Pulsed jet significantly affects the pore pressure of deep formation and then affects the mechanical ROP. In this paper, the effect of jet pulsation on deep pore pressure in the formation is studied by the finite element method. Under the pulsed jet, the maximum relative negative pressure is along the wellbore axis, and the farther it is to the borehole axis, the smaller the relative negative pressure is. With the increase of pulse frequency, the relative negative pressure increases and the maximum point of relative negative pressure moves upward. The optimum pulse frequency is from 50 Hz to 500 Hz. There is a linear relationship between pulse amplitude and relative negative pressure.

Finite Element Simulation of Performance Characteristics of Infinitely Wide Plane Pad Slider Bearing

2009 ◽  
Vol 62-64 ◽  
pp. 637-642 ◽  
Author(s):  
M.H. Oladeinde ◽  
John A. Akpobi
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Element Simulation ◽  
Frictional Force ◽  
Maximum Point ◽  
The Finite Element Method ◽  
Slider Bearing ◽  
Aspect Ratios ◽  
Element Simulation ◽  
Element Method

The paper describes the results of a numerical study using Galerkin’s finite element method on an infinitely wide slider bearing. The analysis is based upon the generalized Reynolds equation with the assumption that the pressure gradient in the lubricating film is negligible in the axial direction. Detailed results for bearing characteristics including pressure, load capacity, frictional force, frictional coefficient as a function of film thickness ratio (aspect ratio), and velocity of slider show that these parameters have a strong influence on the bearing behavior. Specifically, it has been shown that friction coefficient and frictional force increases with lower aspect ratios. Also, higher load carrying and maximum pressure is obtained with increased speed of the slider Point wise comparison of the results obtained using the Finite Element Method and that obtained with second order Finite Difference marching Method using base parameters show that the latter simulation has a maximum point wise error of 0.46% in comparison to 0.32% for Finite Element simulation. It has been shown that the Finite Element Method produces more accurate results. The results are in tabular and graphical forms.

Simulation of tuning graphene plasmonic behaviors by ferroelectric domains for self-driven infrared photodetector applications

Nanoscale ◽  
2019 ◽  
Vol 11 (43) ◽  
pp. 20868-20875 ◽  
Author(s):  
Junxiong Guo ◽  
Yu Liu ◽  
Yuan Lin ◽  
Yu Tian ◽  
Jinxing Zhang ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Interfacial Effect ◽  
Infrared Photodetector ◽  
The Finite Element Method ◽  
Ferroelectric Domains ◽  
Element Method

We propose a graphene plasmonic infrared photodetector tuned by ferroelectric domains and investigate the interfacial effect using the finite element method.

Comparison of Conventional and Pontic Fixed Partial Dentures Over Implants Using the Finite Element Method: Three-Dimensional Analysis of Cortical and Medullary Bone Stress

2020 ◽  
Vol 46 (3) ◽  
pp. 175-181
Author(s):  
Marcelo Bighetti Toniollo ◽  
Mikaelly dos Santos Sá ◽  
Fernanda Pereira Silva ◽  
Giselle Rodrigues Reis ◽  
Ana Paula Macedo ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Medullary Bone ◽  
Principal Stresses ◽  
Bone Stress ◽  
Bone Damage ◽  
Rehabilitation System ◽  
Minimum Requirements

Rehabilitation with implant prostheses in posterior areas requires the maximum number of possible implants due to the greater masticatory load of the region. However, the necessary minimum requirements are not always present in full. This project analyzed the minimum principal stresses (TMiP, representative of the compressive stress) to the friable structures, specifically the vestibular face of the cortical bone and the vestibular and internal/lingual face of the medullary bone. The experimental groups were as follows: the regular splinted group (GR), with a conventional infrastructure on 3 regular-length Morse taper implants (4 × 11 mm); and the regular pontic group (GP), with a pontic infrastructure on 2 regular-length Morse taper implants (4 × 11 mm). The results showed that the TMiP of the cortical and medullary bones were greater for the GP in regions surrounding the implants (especially in the cervical and apical areas of the same region) but they did not reach bone damage levels, at least under the loads applied in this study. It was concluded that greater stress observed in the GP demonstrates greater fragility with this modality of rehabilitation; this should draw the professional's attention to possible biomechanical implications. Whenever possible, professionals should give preference to use of a greater number of implants in the rehabilitation system, with a focus on preserving the supporting tissue with the generation of less intense stresses.

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