CALCULATION OF SWIRLED NONISOTHERMIC LAYER FLOW OF TWO-PHASE NON-NEWTONIAN MEDIUM ON A CONICAL SURFACE

10.12737/3809 ◽  
2014 ◽  
Vol 9 (1) ◽  
pp. 60-64
Author(s):  
Ибятов ◽  
Ravil Ibyatov ◽  
Сиразева ◽  
Daniya Sirazeva
Keyword(s):  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Heterogeneous Medium ◽  
Two Phase ◽  
Conservation Equations ◽  
Longitudinal Coordinate ◽  
System Equations ◽  
Layer Flow ◽  
The Right ◽  
Homogeneous Approximation

We consider the non-isothermic layer flow of two-phase non-Newtonian medium on the inner surface of the conical tube. The flow regime is laminar , axisymmetric and steady. The rheological state of the medium is described by the generalized law Ostwald de Ville. We also took into account the dependence of the temperature of medium consistency. The conservation equations of mass, momentum and energy mechanics of heterogeneous medium is used in quasi-homogeneous approximation. The recorded in biconical coordinate system equations are solved by method of equal costs surfaces. The provisions of equal costs surfaces are determined from the condition of the flow of the medium constancy between them. Conservation equations, written on the flow lines, are simplified and take the form of ordinary differential equations on the longitudinal coordinate. So that to calculate the partial derivatives on the transverse coordinate, which are present in the right part of the differential equations, the grid solutions are presented in the form of series expansion. The system of constructed ordinary differential equations is solved numerically.

scholarly journals An Optimal Control Problem by a Hybrid System of Hyperbolic and Ordinary Differential Equations

Games ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 23
Author(s):  
Alexander Arguchintsev ◽  
Vasilisa Poplevko
Keyword(s):  
Optimal Control ◽  
Differential Equations ◽  
Optimal Control Problem ◽  
Control Problem ◽  
Ordinary Differential Equations ◽  
Hyperbolic Equations ◽  
Control Methods ◽  
The Right ◽  
The Cost ◽  
Optimal Control Methods

This paper deals with an optimal control problem for a linear system of first-order hyperbolic equations with a function on the right-hand side determined from controlled bilinear ordinary differential equations. These ordinary differential equations are linear with respect to state functions with controlled coefficients. Such problems arise in the simulation of some processes of chemical technology and population dynamics. Normally, general optimal control methods are used for these problems because of bilinear ordinary differential equations. In this paper, the problem is reduced to an optimal control problem for a system of ordinary differential equations. The reduction is based on non-classic exact increment formulas for the cost-functional. This treatment allows to use a number of efficient optimal control methods for the problem. An example illustrates the approach.

scholarly journals On the solution of two-sided fractional ordinary differential equations of Caputo type

2016 ◽  
Vol 19 (6) ◽  
Author(s):  
Ma. Elena Hernández-Hernández ◽  
Vassili N. Kolokoltsov
Keyword(s):  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Fractional Differential Equations ◽  
Well Posedness ◽  
Solutions To Equations ◽  
Fractional Differential ◽  
The Right ◽  
Stochastic Representations ◽  
Exit Problems ◽  
Special Case

AbstractThis paper provides well-posedness results and stochastic representations for the solutions to equations involving both the right- and the left-sided generalized operators of Caputo type. As a special case, these results show the interplay between two-sided fractional differential equations and two-sided exit problems for certain Lévy processes.

scholarly journals Methods for solving the initial value problem with a two-sided estimate of the local error

2021 ◽  
pp. 88-92
Author(s):  
Yaroslav Pelekh ◽  
Andrii Kunynets ◽  
Halyna Beregova ◽  
Tatiana Magerovska
Keyword(s):  
Differential Equation ◽  
Numerical Methods ◽  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Initial Value Problem ◽  
Local Error ◽  
Initial Value ◽  
Order Of Accuracy ◽  
Embedded Methods ◽  
The Right

Numerical methods for solving the initial value problem for ordinary differential equations are proposed. Embedded methods of order of accuracy 2(1), 3(2) and 4(3) are constructed. To estimate the local error, two-sided calculation formulas were used, which give estimates of the main terms of the error without additional calculations of the right-hand side of the differential equation, which favorably distinguishes them from traditional two-sided methods of the Runge- Kutta type.

Effects of Oil-Based Nanofluid on a Stretching Surface with Variable Suction and Thermal Conductivity

2017 ◽  
Vol 11 ◽  
pp. 99-109 ◽  
Author(s):  
Christian John Etwire ◽  
Ibrahim Yakubu Seini ◽  
Rabiu Musah
Keyword(s):  
Thermal Conductivity ◽  
Boundary Layer ◽  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Base Fluid ◽  
Stretching Surface ◽  
Third Order ◽  
Suction Parameter ◽  
Layer Flow ◽  
Porous Stretching Surface

The combined effect of suction and thermal conductivity on the boundary layer flow of oil–based nanofluid over a porous stretching surface has been investigated. Similarity techniques were employed in transforming the governing partial differential equations into a coupled third order ordinary differential equations. The higher third order ordinary differential equations were then reduced into a system of first order ordinary differential equations and solved numerically using the fourth order Runge-Kutta algorithm with a shooting method. The results were presented in tabular and graphically forms for various controlling parameters. It was found that increasing the thermal conductivities of the base fluid (oil) and nanoparticle size (CuO) of the nanofluid did not affect the velocity boundary layer thickness but depreciates with suction and permeability. The suction parameter and thermal conductivity of the base fluid also made the thermal boundary layer thinner.

scholarly journals Singular Initial Value Problem for Certain Classes of Systems of Ordinary Differential Equations

2013 ◽  
Vol 2013 ◽  
pp. 1-12
Author(s):  
Josef Diblík ◽  
Josef Rebenda ◽  
Zdeněk Šmarda
Keyword(s):  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Initial Value Problem ◽  
Existence Of Solutions ◽  
Sufficient Conditions ◽  
Asymptotic Formulas ◽  
Asymptotic Behavior Of Solutions ◽  
Initial Value ◽  
Singular Initial Value Problem ◽  
The Right

The paper is devoted to the study of the solvability of a singular initial value problem for systems of ordinary differential equations. The main results give sufficient conditions for the existence of solutions in the right-hand neighbourhood of a singular point. In addition, the dimension of the set of initial data generating such solutions is estimated. An asymptotic behavior of solutions is determined as well and relevant asymptotic formulas are derived. The method of functions defined implicitly and the topological method (Ważewski's method) are used in the proofs. The results generalize some previous ones on singular initial value problems for differential equations.

scholarly journals ANALYSIS OF POSSIBLE CAUSES AND MECHANISMS OF DESTRUCTION OF BUILDING STRUCTURES

2018 ◽  
Vol 14 (1) ◽  
pp. 49-63
Author(s):  
Еvgeniy M. Zveryayev ◽  
Evgeniy A. Larionov
Keyword(s):  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Inverse Method ◽  
Initial Approximation ◽  
Plane Elasticity ◽  
Zero Approximation ◽  
Banach Fixed Point Theorem ◽  
Power Functions ◽  
Transverse Coordinate ◽  
Longitudinal Coordinate

In order to better understand the wave properties of the Timoshenko equation, the derivation of the refined equation from the equations of the plane elasticity problem for a long band is carried out. The simple iterations method is used for the derivation. It includes known methods: the semi-inverse method of Saint-Venant and Picard operator. In accordance with the semi-inverse method, a part of the unknowns is defined, which are interpreted as the values of the initial (zero) approximation. Proceeding from them, a sequential computation is carried out using a sequence of the four Picard operators in such a way that the outputs of the one operator are the inputs for the next. Calculating in this way all the unknowns in the zeroth approximation by the direct integration over the transverse coordinate, the values of the initial approximation are calculated in the first approximation. These quantities are small of the second order with respect to the dimensionless thickness. Expressions for the unknowns are obtained as power functions of the transverse coordinate and as a function of the deriva-tives along the longitudinal coordinate. By the Banach fixed point theorem, the computation process is asymptot-ically convergent one. After this, boundary conditions on the long sides are satisfied by means of the derivatives of the arbitrariness, depending only on the longitudinal coordinate. This gives us the ordinary differential equations for the determination of these arbitrary functions. In turn, the integration constants of the last equations can be found from the conditions on the short sides of the strip. The ordinary differential equations are split into equations for slowly varying and quickly varying quantities. The slowly changing values give the classical solu-tion of the beam oscillations. The quickly varying solutions give the perturbed solutions describing high-frequency oscillations and singularly perturbed wave solutions for time-concentrated effects. Some of these soluions are absent in the Timoshenko equation. It is assumed that the selected shear waves provoke in the buildings subjected to the rapid impacts (shock by airplane, explosions, and seismic movements of the base) the interruptions of interlayers between the floors and subsequent progressive collapse.

scholarly journals BOUNDARY LAYER FLOW AND HEAT TRANSFER WITH VARIABLE VISCOSITY IN THE PRESENCE OF MAGNETIC FIELD

2016 ◽  
Vol 12 (7) ◽  
pp. 6412-6421
Author(s):  
Ajala O.A ◽  
Aseelebe L. O ◽  
Ogunwobi Z. O
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Boundary Layer Flow ◽  
Variable Viscosity ◽  
Physical Parameters ◽  
Flow And Heat Transfer ◽  
Dimensional Boundary ◽  
Layer Flow

A steady two dimensional boundary layer flow and heat transfer with variable viscosity electrically conducting fluid at T in the presence of magnetic fields and thermal radiation was considered. The governing equations which are partial differential equations were transformed into ordinary differential equations using similarity variables, and the resulting coupled ordinary differential equations were solved using collocation method in MAPLE 18. The velocity and temperature profiles were studied graphically for different physical parameters. The effects of the parameters on velocity and temperature profile were showed.

scholarly journals Radiative Boundary Layer Flow in Porous Medium due to Exponentially Shrinking Permeable Sheet

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Paresh Vyas ◽  
Nupur Srivastava
Keyword(s):  
Boundary Layer ◽  
Porous Medium ◽  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Boundary Layer Flow ◽  
Radiative Heat ◽  
Saturated Porous Medium ◽  
Similarity Transformations ◽  
Layer Flow ◽  
Rosseland Approximation

This communication pertains to the study of radiative heat transfer in boundary layer flow over an exponentially shrinking permeable sheet placed at the bottom of fluid saturated porous medium. The porous medium has permeability of specified form. The fluid considered here is Newtonian, without phase change, optically dense, absorbing-emitting radiation but a nonscattering medium. The setup is subjected to suction to contain the vorticity in the boundary layer. The radiative heat flux in the energy equation is accounted by Rosseland approximation. The thermal conductivity is presumed to vary with temperature in a linear fashion. The governing partial differential equations are reduced to ordinary differential equations by similarity transformations. The resulting system of nonlinear ordinary differential equations is solved numerically by fourth-order Runge-Kutta scheme together with shooting method. The pertinent findings displayed through figures and tables are discussed.

scholarly journals An implementation of the Chebyshev series method for the approximate analytical solution of second-order ordinary differential equations

2019 ◽  
pp. 97-103
Author(s):  
О.Б. Арушанян ◽  
С.Ф. Залеткин
Keyword(s):  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Canonical System ◽  
Second Order ◽  
Partial Sums ◽  
Problem Solution ◽  
Chebyshev Series ◽  
Canonical Systems ◽  
The Cauchy Problem ◽  
The Right

Описан один метод по применению рядов Чебышёва для интегрирования канонических систем обыкновенных дифференциальных уравнений второго порядка. Этот метод основан на аппроксимации решения задачи Коши, его первой и второй производных частичными суммами смещенных рядов Чебышёва. Коэффициенты рядов вычисляются итерационным способом с применением соотношений, связывающих коэффициенты Чебышёва решения задачи Коши, а также коэффициенты Чебышёва первой производной решения с коэффициентами Чебышёва правой части системы. Неотъемлемым элементом вычислительной схемы является использование формулы численного интегрирования Маркова для вычисления коэффициентов Чебышёва правой части системы. В статье не только сообщаются результаты, полученные численными расчетами, но и делается упор на высокоточном аналитическом представлении решения в виде частичной суммы ряда на промежутке интегрирования. A method used to apply the Chebyshev series for solving canonical systems of second order ordinary differential equations is described. This method is based on the approximation of the Cauchy problem solution and its first and second derivatives by partial sums of shifted Chebyshev series. The coefficients of these series are determined iteratively using the relations relating the Chebyshev coefficients of the solution and its first derivative with the Chebyshev coefficients found for the right-hand side of the canonical system by application of Markov's quadrature formula. The obtained numerical results are discussed and the high-precision analytical representations of the solution are proposed in the form of partial sums of Chebyshev series on a given integration segment.

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