Green’s Functions in Generalized Micropolar Thermoelasticity

1993 ◽  
Vol 46 (11S) ◽  
pp. S316-S326
Author(s):  
Ranjit S. Dhaliwal ◽  
Jun Wang
Keyword(s):  
General Solution ◽  
Heat Source ◽  
Body Force ◽  
The Body ◽  
Arbitrary Distribution ◽  
Heat Sources ◽  
Infinite Body ◽  
Body Forces ◽  
Micropolar Thermoelasticity ◽  
Short Time

General solution of the generalized micropolar thermoelastic equations has been obtained for arbitrary distribution of the body couples, body forces, and heat sources in an infinite body. Short time solutions have been obtained for the cases of impulsive body force and heat source acting at a point. Numerical values of the short time solutions have been displayed graphically.

Transient Temperature Involving Oscillatory Heat Source With Application in Fretting Contact

2007 ◽  
Vol 129 (3) ◽  
pp. 517-527 ◽  
Author(s):  
Jun Wen ◽  
M. M. Khonsari
Keyword(s):  
Heat Source ◽  
Oscillation Amplitude ◽  
The Body ◽  
Transient Temperature ◽  
Dimensionless Frequency ◽  
Heat Sources ◽  
Infinite Body ◽  
Fitting Method ◽  
Wide Range ◽  
Analytical Expressions

An analytical approach for treating problems involving oscillatory heat source is presented. The transient temperature profile involving circular, rectangular, and parabolic heat sources undergoing oscillatory motion on a semi-infinite body is determined by integrating the instantaneous solution for a point heat source throughout the area where the heat source acts with an assumption that the body takes all the heat. An efficient algorithm for solving the governing equations is developed. The results of a series simulations are presented, covering a wide range of operating parameters including a new dimensionless frequency ω¯=ωl2∕4α and the dimensionless oscillation amplitude A¯=A∕l, whose product can be interpreted as the Peclet number involving oscillatory heat source, Pe=ω¯A¯. Application of the present method to fretting contact is presented. The predicted temperature is in good agreement with published literature. Furthermore, analytical expressions for predicting the maximum surface temperature for different heat sources are provided by a surface-fitting method based on an extensive number of simulations.

scholarly journals Propagation of Thermal Stresses in an Infinite Medium

1959 ◽  
Vol 11 (4) ◽  
pp. 237-244 ◽  
Author(s):  
F. J. Lockett ◽  
I. N. Sneddon
Keyword(s):  
Thermal Stresses ◽  
Infinite Medium ◽  
Nonuniform Distribution ◽  
The Body ◽  
Heat Sources ◽  
Dynamic Stresses ◽  
Elastic Bodies ◽  
State Of Stress ◽  
Body Forces ◽  
Uneven Heating

In the full linear theory of thermoelasticity there is a coupling between the thermal and the purely mechanical effects so that not only does a nonuniform distribution of temperature in the solid produce a state of stress but dynamical body forces or applied surface tractions produce variations in temperature throughout the body. In a recent paper (Eason and Sneddon, (2)) an account was given of the calculation of the dynamic stresses produced in elastic bodies, both infinite and semi-infinite, by uneven heating. In this paper we shall consider the propagation of thermal stresses in an infinite medium when, in addition to heat sources, there are present body forces which vary with the time.

A No-Calibration Approach to Modelling Compressor Blade Rows With Body Forces Employing Artificial Neural Networks

2019 ◽  
Author(s):  
S. Pazireh ◽  
J. J. Defoe
Keyword(s):  
Neural Network ◽  
Body Force ◽  
Incompressible Flows ◽  
The Body ◽  
Analytical Models ◽  
Force Model ◽  
Body Forces ◽  
Viscous Loss ◽  
Artificial Neural ◽  
Modelling Approach

Abstract Body force modelling in numerical simulations of axial compressors and fans has been used extensively in the literature to assess aerodynamic performance in uniform and non-uniform flow at relatively low computational cost. Existing approaches require calibration or, in the case of purely analytical models, are unable to accurately predict losses. It can also be challenging to capture the chordwise loading distribution with existing analytical models. This paper introduces a new body force modelling approach in which blade loading is computed using an isolated-airfoil, analytical model supplemented by a trained artificial-neural-network-based correction factor for finite pitch effects. The loading model is derived from potential flow theory and accounts for both camber and thickness effects; it captures both the overall and local loading. The approach is currently implemented for low-Mach number (incompressible) flows. The body forces causing flow turning derive directly from the corrected loading model. Forces arising from viscous losses are modeled by solving the integral boundary layer equations along streamlines within blade rows based on the fictitious edge velocities computed by the loading model. The viscous loss force is a function of the local dissipation coefficients. The approach is implemented within a traditional finite-volume computational fluid dynamics solver. In this paper, the application is limited to 2D cascades. To assess the approach, results from the body force model are compared to blade-to-blade solutions from MISES. The key findings are (1) that a relatively modest set of training data for the neural network produces a robust finite pitch correction, and (2) that the modelling approach is able to successfully capture the flow turning and losses associated with a variety of low-speed compressor cascades without any calibration specific to the blade row(s) being modeled.

EFFECTS OF BODY FORCES ON THE STRUCTURE AND RHEOLOGY OF ER AND MR FLUIDS

2007 ◽  
Vol 21 (28n29) ◽  
pp. 4841-4848 ◽  
Author(s):  
DANIEL J. KLINGENBERG ◽  
JOHN C. ULICNY ◽  
ANTHONY L. SMITH
Keyword(s):  
Experimental Investigation ◽  
Body Force ◽  
The Body ◽  
Experimental Results ◽  
Centrifugal Forces ◽  
Mr Fluids ◽  
Body Forces ◽  
Particle Level

We employ particle-level simulations to show that body forces, such as gravity or centrifugal forces, can significantly influence the structure and rheology of ER and MR suspensions even when the magnitude of the body force acting on a particle is small compared to the field-induced force. We also report an experimental investigation of the effects of body forces on the structure of ER suspensions. Experimental results agree qualitatively with predictions.

Temperature in Semi-Infinite and Cylindrical Bodies Subjected to Moving Heat Sources and Surface Cooling

1970 ◽  
Vol 92 (3) ◽  
pp. 456-464 ◽  
Author(s):  
N. R. DesRuisseaux ◽  
R. D. Zerkle
Keyword(s):  
Heat Source ◽  
Cylindrical Body ◽  
Heat Sources ◽  
Surface Cooling ◽  
Machining Processes ◽  
Infinite Body ◽  
Entire Surface ◽  
Convective Cooling ◽  
Temperature Distributions ◽  
Analytical Results

The theory of moving heat sources is applied to two models to determine the effect of convective surface cooling on temperature distributions. The models chosen consist of a translating semi-infinite body and a rotating cylindrical body, each having a band heat source acting on a portion of the surface and convective cooling acting over the entire surface. The analytical results can be utilized to predict temperature distributions occurring in certain machining processes or other processes involving heat sources.

scholarly journals The mechanics of gravity-driven faulting

2010 ◽  
Vol 2 (1) ◽  
pp. 105-144 ◽  
Author(s):  
L. Barrows ◽  
V. Barrows
Keyword(s):  
Density Distribution ◽  
Gravitational Potential ◽  
Elastic Strain ◽  
Body Force ◽  
Tectonic Stress ◽  
The Body ◽  
Gravitational Potential Energy ◽  
Body Forces ◽  
Elastic Rebound ◽  
Earthquake Model

Abstract. Faulting can result from either of two different mechanisms. These involve fundamentally different energetics. In elastic rebound, locked-in elastic strain energy is transformed into the earthquake (seismic waves plus work done in the fault zone). In force-driven faulting, the forces that create the stress on the fault supply work or energy to the faulting process. Half of this energy is transformed into the earthquake and half goes into an increase in locked-in elastic strain. In elastic rebound the locked-in elastic strain drives slip on the fault. In force-driven faulting it stops slip on the fault. Tectonic stress is reasonably attributed to gravity acting on topography and the Earth's lateral density variations. This includes the thermal convection that ultimately drives plate tectonics. Mechanical analysis has shown the intensity of the gravitational tectonic stress that is associated with the regional topography and lateral density variations that actually exist is comparable with the stress drops that are commonly associated with tectonic earthquakes; both are in the range of tens of bar to several hundred bar. The gravity collapse seismic mechanism assumes the fault fails and slips in direct response to the gravitational tectonic stress. Gravity collapse is an example of force-driven faulting. In the simplest case, energy that is released from the gravitational potential of the stress-causing topography and lateral density variations is equally split between the earthquake and the increase in locked-in elastic strain. The release of gravitational potential energy requires a change in the Earth's density distribution. Gravitational body forces are solely dependent on density so a change in the density distribution requires a change in the body forces. This implies the existence of volumetric body-force displacements. The volumetric body-force displacements are in addition to displacements generated by slip on the fault. They must exist if gravity participates in the energetics of the faulting process. From the perspective of gravitational tectonics, the gravity collapse mechanism is direct and simple. The related mechanics are more subtle. If gravity is not deliberately and explicitly included in an earthquake model, then gravity is locked out of the energetics of the model. The earthquake model (but not necessarily the physical reality) is then elastic rebound.

Stress-Intensity Factors for an Internal Semi-Elliptical Surface Crack in Cylindrical Pressure Vessels

1995 ◽  
Vol 117 (3) ◽  
pp. 213-221 ◽  
Author(s):  
D.-H. Chen ◽  
H. Nisitani ◽  
K. Mori
Keyword(s):  
Surface Crack ◽  
Body Force ◽  
Crack Problem ◽  
Pressure Vessels ◽  
The Body ◽  
Intensity Factors ◽  
Infinite Body ◽  
Force Method ◽  
Body Force Method ◽  
Point Forces

In this paper, the surface crack problem in a cylinder subjected to internal pressure is solved. The analysis is based on the body force method, but it is different from the conventional body force method in the following point. That is, the body forces to be distributed continuously on the assumed boundaries in an infinite body are approximated by some discrete point forces acting on the outside of the assumed boundaries. By using this method combined with the resultant force boundary conditions, solutions with high accuracy are obtained.

An Exact Solution for Classic Coupled Thermoelasticity in Cylindrical Coordinates

2011 ◽  
Vol 133 (5) ◽  
Author(s):  
M. Jabbari ◽  
H. Dehbani ◽  
M. R. Eslami
Keyword(s):  
Exact Solution ◽  
Heat Source ◽  
Analytical Method ◽  
Loading Condition ◽  
Body Force ◽  
The Body ◽  
Cylindrical Coordinates ◽  
Coupled Thermoelasticity ◽  
Coupled Equations ◽  
Symmetric Loading

In this paper, the classic coupled thermoelasticity model of hollow and solid cylinders under radial-symmetric loading condition (r,t) is considered. A full analytical method is used, and an exact unique solution of the classic coupled equations is presented. The thermal and mechanical boundary conditions, the body force, and the heat source are considered in the most general forms, where no limiting assumption is used.

An Exact Solution for Classic Coupled Thermoelasticity in Spherical Coordinates

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
M. Jabbari ◽  
H. Dehbani ◽  
M. R. Eslami
Keyword(s):  
Exact Solution ◽  
Heat Source ◽  
Loading Condition ◽  
Body Force ◽  
The Body ◽  
Spherical Coordinates ◽  
Coupled Thermoelasticity ◽  
Coupled Equations ◽  
Symmetric Loading ◽  
Solid Spheres

In this paper, the classic coupled thermoelasticity model of hollow and solid spheres under radial-symmetric loading condition (r,t) is considered. A full analytical method is used and an exact unique solution of the classic coupled equations is presented. The thermal and mechanical boundary conditions, the body force, and the heat source are considered in the most general forms, where no limiting assumption is used. This generality allows to simulate a variety of applicable problems.

PLANETARY SELF-ORGANIZATION

2020 ◽  
Vol 42 (3) ◽  
pp. 271-282
Author(s):  
OLEG IVANOV
Keyword(s):  
Dynamical System ◽  
Heat Source ◽  
Mantle Convection ◽  
Plate Tectonics ◽  
Rotation Speed ◽  
Self Organization ◽  
Heat Sources ◽  
Kinematic Parameters ◽  
The Earth ◽  
New Type

The general characteristics of planetary systems are described. Well-known heat sources of evolution are considered. A new type of heat source, variations of kinematic parameters in a dynamical system, is proposed. The inconsistency of the perovskite-post-perovskite heat model is proved. Calculations of inertia moments relative to the D boundary on the Earth are given. The 9 times difference allows us to claim that the sliding of the upper layers at the Earth's rotation speed variations emit heat by viscous friction.This heat is the basis of mantle convection and lithospheric plate tectonics.

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