Wyniki wyszukiwania - Biblioteka Nauki

1

Modelowanie i symulacja cewki nieliniowej ze stratami w żelazie

100%

Kolańska-Płuska J. , Grochowicz B.

Prace Instytutu Elektrotechniki

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2016

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tom Z. 272

217--226

PL

Praca dotyczy badania dynamiki obwodu z cewką nieliniową z uwzględnieniem strat w żelazie. W pracy został przedstawiony model cewki oraz opis za pomocą zmiennych stanu. Przedstawiono również program do badania dynamiki cewki opracowany w środowisku C#, w którym do rozwiązania układu równań różniczkowych nieliniowych modelujących cewkę nieliniową ze stratami w żelazie zastosowano metodę niejawną RADAU IIA różnych rzędów.

EN

Solving rigid differential equations systems should be performed with the application of implicit or semi-explicit methods. As proven in the example given in this paper – the implicit RADAU IIA methods can be successfully applied for the purpose of solving the rigid non-linear systems. The high-order methods up to 11 cause that the application performs relatively large integration steps in pursuit of the steady state that is comparable with the explicit methods. Furthermore, the number of iterations and computation time for a sample non-linear equations formulated for a coil with iron losses is comparable to other methods such as, e.g., multistep Gear method. Also a sample test has proved that the implicit Runge-Kutta methods can be competitive for the purpose of research regarding electrical systems described with the rigid differential equations compared to the multistep Gear method.

2

Investigation on numerical solution for a robot arm problem

100%

Ponalagusamy R. , Senthilkumar S.

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tom Vol. 3, No. 3

34-40

EN

The aim of this article is focused on providing numerical solutions for a Robot arm problem using the Runge-Kutta sixth-order algorithm. The parameters involved in problem of a Robot control have also been discussed through RKsixth-order algorithm. The précised solution of the system of equations representing the arm model of a robot has been compared with the corresponding approximate solutions at different time intervals. Experimental results and comparison show the efficiency of the numerical integration algorithm based on the absolute error between the exact and approximate solutions. The stability polynomial for the test equation ( is a complex Number) using RK-Butcher algorithm obtained by Murugesan et. al. [Murugesan K., Sekar S., Murugesh V., Park J.Y., "Numerical solution of an Industrial Robot arm Control Problem using the RK-Butcher Algorithm", International Journal of Computer Applications in Technology, vol.19, no. 2, 2004, pp. 132-138] is not correct and the stability regions for RK-fourth order (RKAM) and RK-Butcher methods have been presented incorrectly. They have made a mistake in determining the range for real parts of (h is a step size) involved in the test equation for RKAM and RK-Butcher algorithms. In the present paper, a corrective measure has been taken to obtain the stability polynomial for the case of RK-Butcher algorithm, the ranges for the real part of and to present graphically the stability regions of the RKAM and the RK-Butcher methods. The stability polynomial and stability region of RK-Sixth order are also reported. Based on the numerical results it is observed that the error involved in the numerical solution obtained by RK-Sixth order is less in comparison with that obtained by the RK-Fifth order and RK-Fourth order respectively.

3

A study of MHD fluid with second order slip and thermal flow over a nonlinear stretching sheet

100%

Jauhri S. , Mishra U.

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tom Vol. 27, no. 2

98--114

EN

An electrically conducted viscous incompressible nanofluid flow caused by the nonlinear stretching surface with stagnation flow has been investigated numerically. The effect of Brownian motion and thermophoresis on the nanofluid is also incorporated. The governing partial differential equations with nonlinear second order boundary conditions are solved by the fourth order Runge-Kutta technique using MATLAB programming. The effect of the radiation parameter (Rd), stretching parameter (n), Brownian motion parameter (Nb), thermophoresis parameter (Nt) on temperature, velocity and mass transfer are shown graphically. The influence of some of these parameters on the local Nusselt number (−𝜃′(0)) and local Sherwood number (−𝜙′(0)) are shown by the graphs.

4

Frictional Auto-vibrations in a Contact Thermoelastic Problem in Wear Conditions

100%

Awrejcewicz J. , Pyryev Y.

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tom Vol. 21

79--82

5

Issledovanie dinamiki ustrojjstva dlja narezanija rez'by

100%

Gevko B. , Djachun A. , Marchuk N.

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tom 18

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nr 1

6

Symplectic integrators for cascade of mass-spring system

84%

Jopek H. , Stręk T.

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2006

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tom Vol. 22

155--160

7

Effect of viscous dissipation and thermal radiation on heat transfer over a non-linearly stretching sheet through porous medium

84%

Nandeppanavar M. M. , Siddalingappa M. N.

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tom Vol. 18, no. 2

461--474

EN

In this present paper, we have discussed the effects of viscous dissipation and thermal radiation on heat transfer over a non-linear stretching sheet through a porous medium. Usual similarity transformations are considered to convert the non-linear partial differential equation of motion and heat transfer into ODE’s. Solutions of motion and heat transfer are obtained by the Runge-Kutta integration scheme with most efficient shooting technique. The graphical results are presented to interpret various physical parameters of interest. It is found that the velocity profile decreases with an increase of the porous parameter asymptotically. The temperature field decreases with an increase in the parametric values of the Prandtl number and thermal radiation while with an increase in parameters of the Eckert number and porous parameter, the temperature field increases in both PST (power law surface temperature) and PHF (power law heat flux) cases. The numerical values of the non-dimensional wall temperature gradient and wall temperature are tabulated and discussed.

8

Numerical predictions of laminar flow and free convection heat transfer from an isothermal vertical flat plate

67%

Belhocine A. , Stojanovic N. , Abdullah O. I.

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2022

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tom LXIX, nr 4

749--773

EN

In this present work, the laminar free convection boundary layer flow of a two-dimensional fluid over the vertical flat plate with a uniform surface temperature has been numerically investigated in detail by the similarity solution method. The velocity and temperature profiles were considered similar to all values and their variations are as a function of distance from the leading edge measured along with the plate. By taking into account this thermal boundary condition, the system of governing partial differential equations is reduced to a system of non-linear ordinary differential equations. The latter was solved numerically using the Runge-Kutta method of the fourth-order, the solution of which was obtained by using the FORTRAN code on a computer. The numerical analysis resulting from this simulation allows us to derive some prescribed values of various material parameters involved in the problem to which several important results were discussed in depth such as velocity, temperature, and rate of heat transfer. The definitive comparison between the two numerical models showed us an excellent agreement concerning the order of precision of the simulation. Finally, we compared our numerical results with a certain model already treated, which is in the specialized literature.

9

Modelowanie matematyczne procesów nieustalonych w układzie przeniesienia napędu z wałem Cardana w elektrycznym samochodzie ciężarowym

67%

Chaban A.

Przegląd Elektrotechniczny

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2023

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tom R. 99, nr 12

74--77

PL

W pracy opracowano model matematyczny układu przeniesienia napędu samochodu ciężarowego z napędem na tylną oś z uwzględnieniem ruchu wału napędowego, który zawiera przegub Cardana. Główny akcent w modelu postawiony jest na uwzględnienie rotacyjnych ruchów w wale podczas ruchu samochodu w złożonych warunkach pracy. Na podstawie modelu analizowane są dynamiczne stany pracy wału samochodu jadącego po różnych drogach zarówno w stanach statycznych, jak i dynamicznych. Równania stanu transmisji ruchu całkowali się przez metodę Runge-Kutta czwartego rzędu. Przedstawiono wyniki symulacji komputerowej w postaci rysunków, które są analizowane.

EN

There is developed mathematical model of transmission for rear-wheel electric cargo truck taking into account motion of driving shaft including Cardan joints. Model focuses on consideration of the rotary, motion in the shaft in difficult working conditions. There are analyzed dynamic conditions of shaft operating on the flat and rough roads in the both states: dynamic and static as well. Mathematical model is realized by the fourth order Runge-Kutta method. Computer simulation results are demonstrated and analyzed in the figures.