scholarly journals Complex large-scale convection of a viscous incompressible fluid with heat exchange according to Newton’s law

2017 ◽  
Author(s):  
A. V. Gorshkov ◽  
E. Yu. Prosviryakov
Keyword(s):  
Heat Exchange ◽  
Incompressible Fluid ◽  
Large Scale ◽  
Viscous Incompressible Fluid ◽  
Newton's Law ◽  
Newton’S Law

scholarly journals It is Not Easy to Replace Newtonian Gravitational Theory!

1988 ◽  
Vol 130 ◽  
pp. 602-603
Author(s):  
D. Gerbal ◽  
H. Siroussezia
Keyword(s):  
Large Scale ◽  
Gravitational Theory ◽  
Large Scale Structures ◽  
Newton's Law ◽  
Newton’S Law ◽  
Theory Of Gravitation ◽  
Scale Structures ◽  
Image Position

The great amount of unseen dynamical matter in large scale structures is derived from: the Newton's law of inertia and the theory of gravitation. But none of these law has been tested on scale larger than r > 10Kpc. It is then tempting to modify them following: where g(x) is a phenomenological function.

scholarly journals Reverse Task of Heat Conductivity for the Semilimited Bar

2019 ◽  
pp. 27-31
Author(s):  
O. Shevchenko
Keyword(s):  
Thermal Conductivity ◽  
Inverse Problem ◽  
Heat Exchange ◽  
Boundary Conditions ◽  
Heat Conductivity ◽  
Algebraic Equations ◽  
Newton's Law ◽  
Newton’S Law ◽  
Solid Bodies

The article concerns methods and formulas for the calculation of the coefficient of thermal conductivity of solid bodies using the known solutions of direct thermal conductivity tasks. The solution to the inverse problem of heat conductivity is based on the quite complicated methods including both hyperbolic functions and finite-difference methods. Under certain experimental conditions, the task is simplified at the regular thermal modes of 1, 2, or 3 types. Thus final formulas are simplified to algebraic equations. The simplification of the inverse problem of heat conductivity to algebraic equations is possible using other approaches. These me­thods are based on the analysis of the reference points, zero values of temperature distribution function, function inflection points, and its first and second derivatives. Here, we present formulas for the calculations of the temperature field on the assumption of the direct task solution for the half-bounded bar under the pulsed heating followed the re-definition of the boundary conditions. The article describes two methods in which solutions are reduced to simple algebraic formulas when using the specified points on hea­ting thermograms of test examples. These solutions allow algebraic deriving of simple relations for inverse problems of determination of thermophysical characteristics of solid bodies. The calculation formulas are given for the determination of the heat conductivity coefficient determination by two methods: by value of temperature, coordinate, and two moments at which this temperature is reached. The second method uses the values of two coordinates of the test sample in two different points where the equal temperature is reached at different points in time. The final solution of the equation is logarithmic. The analysis of known methods and techniques shows that experimental methods are oriented on the technical implementation and based on facilities of available equipment and instruments. Existing experimental techniques are based on specific constructions of measuring facilities. Simultaneously, there are well-studied methods of solution of thermal conductivity standard tasks set out in fundamental issues. The theoretical methods come from axioms, equations, and theoretical postulates, and they give the solution of inverse tasks of thermal conductivity. This work uses the solutions of direct tasks presented in the monograph by A.V.Lykov “The theory of heat conductivity”. These solutions have a good theoretical background and experts’ credit. The boundary conditions of the problem are next: the half-bounded thin bar is given. The side surface of the bar has a thermal insulation. At the initial moment, the instant heat source acts on the bar in its section at some distance from its end. Heat exchange occurs between the environment and the end of the bar according to Newton’s law. The initial (relative) temperature of the bar is accepted equal to zero. The heat exchange between the free end face of the bar and the environment is gone according to Newton’s law.

scholarly journals Isothermal layered flows of a viscous incompressible fluid with spatial acceleration in the case of three Coriolis parameters

2020 ◽  
pp. 29-46
Author(s):  
N. V. Burmasheva ◽  
◽  
E. Yu. Prosviryakov ◽  
Keyword(s):  
Incompressible Fluid ◽  
Compatibility Condition ◽  
Large Scale ◽  
Stokes Equations ◽  
Viscous Incompressible Fluid ◽  
Navier Stokes ◽  
Arbitrary Form ◽  
Overdetermined System ◽  
Navier Stokes Equations ◽  
Fluid Medium

We study the solvability of the overdetermined system of Navier–Stokes equations, supple-mented by the incompressibility equation, which is used to describe isothermal large-scale shear flows of a rotating viscous incompressible fluid. Large–scale flows are studied in a thin-layer ap-proximation (the vertical velocity of the fluid is assumed to be zero). The rotation of a continuous fluid medium is described by three Coriolis parameters. The solution of the reduced system of Na-vier–Stokes equations is constructed in the Lin–Sidorov–Aristov class. In this case, both nonzero components of the velocity vector, the pressure and temperature fields are assumed to be full linear forms of two Cartesian coordinates, and the dependence on the third Cartesian coordinate has an arbitrary form (including non-polynomial). It is shown that the nonlinear overdetermined system of Navier–Stokes equations and of the incompressibility equation in the framework of the Lin–Sidorov–Aristov class reduces to the equivalent nonlinear overdetermined system of ordinary dif-ferential equations, in which the components of the hydrodynamic fields act as unknown functions. The compatibility condition for the equations of the resulting system is derived. It is shown that, if this compatibility condition is fulfilled, the system has a unique solution, and the spatial accelera-tions in both variables (the linearity with respect to them was postulated when choosing the solution class) prove to be constant functions. These results are a generalization of similar results obtained earlier in the study of solvability in the cases of one and two Coriolis parameters.

The effect of the temperature distribution along the perimeter of the boundary on the the flow in the convective Rayleigh-Benard cell

2011 ◽  
Vol 8 (1) ◽  
pp. 116-123
Author(s):  
V.L. Malyshev ◽  
E.F. Moiseeva ◽  
K.V. Moiseyev
Keyword(s):  
Natural Convection ◽  
Heat Exchange ◽  
Temperature Distribution ◽  
Incompressible Fluid ◽  
Viscous Incompressible Fluid ◽  
Maximum Speed ◽  
Two Dimensional ◽  
Rayleigh Benard ◽  
Dimensional Cell

This paper is devoted to the study of the natural convection of a viscous incompressible fluid in a two-dimensional cell with combined vertical and horizontal heating in symmetrical and asymmetrical cases; investigation of the dependence of the maximum speed and intensity of heat exchange on different heating regimes.

scholarly journals New explanation for accelerated expansion and flat galactic rotation curves

2020 ◽  
Vol 80 (1) ◽  
Author(s):  
Ahmad Sheykhi
Keyword(s):  
Large Scale ◽  
Friedmann Equation ◽  
Accelerated Expansion ◽  
Dark Side ◽  
Galactic Rotation ◽  
Rotation Curves ◽  
Galactic Rotation Curves ◽  
Newton's Law ◽  
Newton’S Law ◽  
Relativistic Regime

AbstractEmploying the non-additive Tsallis entropy, $$S\sim A^{\beta }$$S∼Aβ, for the large-scale gravitational systems, we disclose that in the cosmological scales both the Friedmann equation and the equation of motion for Newtonian cosmology get modified, respectively. We then derive the modified Newton’s law of gravitation which is valid on large scales. We show that, in the relativistic regime, the modified Friedmann equation admits an accelerated expansion, for a universe filled with ordinary matter, without invoking any kind of dark energy, provided the non-extensive parameter is chosen $$\beta <1/2$$β<1/2. In the non-relativistic regime, however, the modified Newton’s law of gravitation can explain the flat galactic rotation curves without invoking particle dark matter provided $$\beta \lesssim 1/2$$β≲1/2. Our study may be regarded as an alternative explanation for the “dark side of the universe”, through modification of the gravitational field equations.

scholarly journals Ether Dynamics and Unification of Gravitational and Electromagnetic forces

2020 ◽  
pp. 1-16
Author(s):  
Ling Jun Wang
Keyword(s):  
Incompressible Fluid ◽  
Electromagnetic Fields ◽  
Lorentz Force ◽  
Direct Contact ◽  
Continuous Medium ◽  
Gravitational Interaction ◽  
Electromagnetic Forces ◽  
Unification Theory ◽  
Newton's Law ◽  
Newton’S Law

Recently we have presented a theory of unification of gravitational and electromagnetic fields based on the generalization of Newton’s law to include a dynamic term similar to the Lorentz force of electrodynamics[1]. The unification is convincing. The generalization based on similarity of Newton’s law and Coulomb’s law, however, is speculative although reasonable and compelling. In this article, we have presented a derivation of the dynamic term of gravitation based on our newly proposed ether dynamics, which removes the speculative nature of dynamic term and perfects the unification theory. It turns out that the gravitational interaction is transmitted through the space medium ether. An object in ether is in direct contact with the ether, causing it to move like a highly viscous and incompressible fluid. The movement of ether propagates thorough space like a continuous medium, exerting a force on any object in ether.

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