Theory of Viscoplastic Lubrication: Part 2—Applications

1992 ◽  
Vol 114 (3) ◽  
pp. 477-484 ◽  
Author(s):  
W. R. D. Wilson ◽  
X. B. Huang

The Reynolds equations for viscoplastic lubricants can be quite complex, involving multiple branches which depend on the form of the boundary conditions invoked in their development. Methods of visualizing and understanding the branching problem are explored. This information is used, together with the Reynolds equations developed in the companion paper, in analyses of the lubrication of a wide slider bearing and a metalforming inlet zone. The results of these analyses are used to draw general conclusions regarding the influence of different types of non-Newtonian behavior.

1996 ◽  
Vol 33 (4-5) ◽  
pp. 309-313
Author(s):  
Jan Šálek ◽  
František Marcián ◽  
Iman Elazizy

Vegetative root zone methods are based on self-purifying processes that take place in the soil, wetland and vegetation containing water media. Our studies are concentrated on the course of puryfying in relation with the length of the filtration bed and on the progress of eliminating the ammoniacal pollution. The research proved that the essential part of the puryfying process takes place within the inlet zone (Figs 1 and 2). The decomposition of ammonia proceeds very slowly. The process of nitrification is affected by the lack of oxygen in the filtration media. To improve the effectiveness of vegetative root zone methods we suggest specific steps: an adjustment of the inlet zone, a system of cascades, a water level pulsation system and combinations of different types and arrangements of vegetative root zones.


2022 ◽  
Vol 14 (1) ◽  
pp. 30
Author(s):  
Hazrat Ali ◽  
Md. Kamrujjaman ◽  
Md. Shafiqul Islam

This study proposed a scheme originated from the Galerkin finite element method (GFEM) for solving nonlinear parabolic partial differential equations (PDEs) numerically with initial and different types of boundary conditions. The scheme is applied generally handling the nonlinear terms in a simple way and throwing over restrictive assumptions. The convergence and stability analysis of the method are derived. The error of the method is estimated. In the series, eminent problems are solved, such as  Fisher's equation, Newell-Whitehead-Segel equation, Burger's equation, and  Burgers-Huxley equation to demonstrate the validity, efficiency, accuracy, simplicity and applicability of this scheme. In each example, the comparison results are presented both numerically and graphically


Author(s):  
Rabi Pathak

The Formula Student competitions are held everyyear. This paper is the result of the analysis done on the sample car design that can be presented in the Formula Student competition. The purpose of the paper is to provide a final summary on chassis analysis and structural performance. It also talks about all the important analysis that is to be done on a Formula Student car to make it safe and perform well on the track. The design has been made such that it focusses on maximum adjustability, reliability, performance, safety, weight reduction and ease of manufacturing. The analysis was done to make sure the objectives of design are fulfilled. After going through many papers, documents, blogs and videos we found that many people get confused about the loading conditions and boundary conditions for different types of tests so this paper prioritizes to make people understand about those conditions as well as about the major tests required to perform complete analysis of Formula Student cars. The weight of the chassis was calculated as 36 kg approximately according to the data obtained from design modeler of Ansys workbench as well as Solidworks. The design sustained all the loading conditions and passed all the tests. Thus, one of the objective of this paper is to help other universities and passionate students to successfully design and analyze their cars that can pass all necessary tests included in the paper. KEYWORDS—Formula Student; FEA; Boundary Conditions; Loading Conditions; Ansys; Solidworks


2019 ◽  
Vol 97 ◽  
pp. 03003
Author(s):  
Anna Avershyeva ◽  
Sergey Kuznetsov

A mathematical model for analyzing Lamb waves propagating in stratified media with arbitrary elastic anisotropy is worked out. The model incorporates a combined Fundamental Matrix (FM) and Modified Transfer Matrix (MTM) methods. Multilayered unbounded plates with different types of boundary conditions imposed on the outer surfaces are considered. Closed form fundamental matrices and secular equations for dispersion relations are derived.


Author(s):  
M. Afzal ◽  
I. Lopez Arteaga ◽  
L. Kari ◽  
V. Kharyton

This paper investigates the damping potential of strip dampers on a real turbine bladed disk. A 3D numerical friction contact model is used to compute the contact forces by means of the Alternate Frequency Time domain method. The Jacobian matrix required during the iterative solution is computed in parallel with the contact forces, by a quasi-analytical method. A finite element model of the strip dampers, that allows for an accurate description of their dynamic properties, is included in the steady-state forced response analysis of the bladed disk. Cyclic symmetry boundary conditions and the multiharmonic balance method are applied in the formulation of the equations of motion in the frequency domain. The nonlinear forced response analysis is performed with two different types of boundary conditions on the strip: (a) free-free and (b) elastic, and their influence is analyzed. The effect of the strip mass, thickness and the excitation levels on the forced response curve is investigated in detail.


2014 ◽  
Vol 1006-1007 ◽  
pp. 83-87
Author(s):  
Zhong Guo Wang ◽  
Guang Yu Zhang ◽  
Yi Qing Li ◽  
De Kai Zhou ◽  
Wen Ping Song

Layered injection commissioning technology has become a key factor to the oil production. For different types of formations, the paper analyzes the absorbent law in different homogeneous formations with different boundary conditions. The paper also creates a composite reservoir model, and then describes changes of absorbent law under coupling effect. The method to do all of the above work is to solve the equation of dimensionless bottomhole pressure in different formation and boundary conditions.


1997 ◽  
Vol 119 (4) ◽  
pp. 603-608 ◽  
Author(s):  
Y. C. Qu ◽  
L. Cheng ◽  
D. Rancourt

This paper presents an experimental assessment of the Tip Excitation Technique (TET) introduced in a companion paper. The aim of the technique is to measure the rotational compliance of attached plane structures. Following the guidelines established on the basis of a numerical study in the companion paper, experimental measurements were performed on a rectangular plate and results were compared with numerical simulations. The investigation focuses on the general performance of the technique, on the different types of excitation used and on other factors necessary to ensure accurate results. In addition, an error analysis is conducted to demonstrate the sensitivity of the results to biased measurement quantities. It is concluded that the proposed technique can be used in the low to middle frequency range, where relatively strong modal behavior is involved.


Author(s):  
Tugce Akkaya ◽  
Wim T. van Horssen

In this paper, initial boundary value problems for a linear string and beam equation are considered. The main aim is to study the reflection of an incident wave at the boundary and the damping properties for different types of boundary conditions such as a mass-spring-dashpot for semi-infinite strings, and pinned, sliding, clamped and damping boundary conditions for semi-infinite beams. The system of transverse vibrations are divided into model 1 and model 2 which are described as a string problem and beam problem, respectively. In order to construct explicit solutions of the boundary value problem for the first model the D’Alembert method will be used to the one dimensional wave equation on the semi-infinite domain, and for the second model the method of Laplace transforms will be applied to a beam equation on a semi-infinite domain. It will be shown how waves are damped and reflected for different types of boundaries and how much energy is dissipated at the boundary.


Geophysics ◽  
1980 ◽  
Vol 45 (5) ◽  
pp. 895-904 ◽  
Author(s):  
Robert W. Clayton ◽  
Björn Engquist

The standard boundary conditions used at the sides of a seismic section in wave‐equation migration generate artificial reflections. These reflections from the edges of the computational grid appear as artifacts in the final section. Padding the section with zero traces on either side adds to the cost of migration and simply delays the inevitable reflections. We develop stable absorbing boundary conditions that annihilate almost all of the artificial reflections. This is demonstrated analytically and with synthetic examples. The absorbing boundary conditions presented can be used with any of the different types of finite‐difference wave‐equation migration, at essentially no extra cost.


1983 ◽  
Vol 105 (1) ◽  
pp. 42-49 ◽  
Author(s):  
P. D. Metz

A FORTRAN computer program called GROCS (Ground Coupled Systems) has been developed to study three-dimensional underground heat flow. Features include the use of up to 30 finite elements or “blocks” of earth which interact via finite difference heat flow equations and a subprogram which sets realistic time and depth-dependent boundary conditions. No explicit consideration of moisture movement or freezing is given. GROCS has been used to model the thermal behavior of buried solar heat storage tanks (with and without insulation) and serpentine pipe fields for solar heat pump space conditioning systems. The program is available independently or in a form compatible with specially written TRNSYS component TYPE subroutines. This paper first describes the approach taken in the design of GROCS, the mathematics contained and the program architecture. Then, the operation of the stand-alone version is explained. Finally, the validity of GROCS is discussed. A companion paper serves as a user’s guide to the TRNSYS-compatible subroutine version.


Sign in / Sign up

Export Citation Format

Share Document